Unable to update npm using npm i -g npm to update

While using npm i -g npm to update to update my npm i am getting permission denied issues.
Following is the trace what i am getting

MacBook-Pro:mongodb-stress-test experimental$ npm i -g npm to update
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/lru-cache
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/agentkeepalive
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/http-proxy-agent
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/https-proxy-agent
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/node-fetch-npm/node_modules/encoding/node_modules/iconv-lite
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/socks-proxy-agent
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/minimatch/node_modules/brace-expansion/node_modules/balanced-match
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/minimatch/node_modules/brace-expansion
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/request/node_modules/har-validator/node_modules/har-schema
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/request/node_modules/har-validator/node_modules/ajv
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/request/node_modules/performance-now
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/node-fetch-npm
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/npm-pick-manifest
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/string-width
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/ansi-align
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/configstore
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/registry-auth-token
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/registry-auth-token/node_modules/rc/node_modules/deep-extend
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/registry-url/node_modules/rc/node_modules/deep-extend
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/http-proxy-agent/node_modules/agent-base/node_modules/semver
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/https-proxy-agent/node_modules/agent-base/node_modules/semver
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/https-proxy-agent/node_modules/extend
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/node-fetch-npm/node_modules/json-parse-helpfulerror
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/node-fetch-npm/node_modules/json-parse-helpfulerror/node_modules/jju
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/socks-proxy-agent/node_modules/agent-base/node_modules/semver
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/socks-proxy-agent/node_modules/extend
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-fs
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-fs/node_modules/pump
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-fs/node_modules/pump/node_modules/end-of-stream
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-stream
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-stream/node_modules/bl
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/request/node_modules/http-signature/node_modules/jsprim/node_modules/assert-plus
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/request/node_modules/safe-buffer
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/ansi-align/node_modules/string-width
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/configstore/node_modules/write-file-atomic
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/got/node_modules/safe-buffer
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/registry-auth-token/node_modules/safe-buffer
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/lazy-req
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/http-proxy-agent/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/https-proxy-agent/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/node-fetch-npm/node_modules/encoding/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/node-fetch-npm/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/socks-proxy-agent/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/minimatch/node_modules/brace-expansion/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/minimatch/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/request/node_modules/har-validator/node_modules/ajv/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/string-width/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/widest-line/node_modules/string-width/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/chalk/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/configstore/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/registry-auth-token/node_modules/rc/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/registry-url/node_modules/rc/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/make-fetch-happen/node_modules/node-fetch-npm/node_modules/json-parse-helpfulerror/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-fs/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-fs/node_modules/pump/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/pacote/node_modules/tar-stream/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/ansi-align/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/got/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/registry-auth-token/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/chalk/node_modules/has-ansi
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/ansi-align/node_modules/string-width/node_modules
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules/npm/node_modules/update-notifier/node_modules/boxen/node_modules/ansi-align/node_modules/string-width/node_modules/is-fullwidth-code-point/node_modules
npm ERR! path /usr/local/lib/node_modules/npm/node_modules/lru-cache
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access
npm ERR! Error: EACCES: permission denied, access '/usr/local/lib/node_modules/npm/node_modules/lru-cache'
npm ERR!  { Error: EACCES: permission denied, access '/usr/local/lib/node_modules/npm/node_modules/lru-cache'
npm ERR!   errno: -13,
npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'access',
npm ERR!   path: '/usr/local/lib/node_modules/npm/node_modules/lru-cache' }
npm ERR! 
npm ERR! Please try running this command again as root/Administrator.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/experimental/.npm/_logs/2017-10-23T04_18_39_893Z-debug.log