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Unhandled rejection Error:
Unhandled rejection Error: EACCES: permission denied, mkdir ‘/Users/bhimashankarvibhute/.npm/_cacache/index-v5/66/8c’
There is an open issue with installing global packages using sudo leaving behind files with the wrong ownership.
The short version is run this to fix the ownership, then try your install again:
sudo chown -R $(whoami) ~/.npm