To install Node.js, type the following command in your terminal:

sudo apt-get install nodejs

Then install the Node package manager, npm:

sudo apt-get install npm

Create a symbolic link for node, as many Node.js tools use this name to execute.

sudo ln -s /usr/bin/nodejs /usr/bin/node

Now we should have both the Node and npm commands working:

$ node -v
v0.10.25
$ npm -v
1.3.10

reference: https://www.hostingadvice.com/how-to/install-nodejs-ubuntu-14-04/#ubuntu-package-manager