number-is-nan 
ES2015
Number.isNaN()ponyfill
Install
$ npm install --save number-is-nan
Usage
var numberIsNan = require('number-is-nan');
numberIsNan(NaN);
//=> true
numberIsNan('unicorn');
//=> false
License
MIT 
Sindre Sorhus
ES2015
Number.isNaN()ponyfill
$ npm install --save number-is-nan
var numberIsNan = require('number-is-nan');
numberIsNan(NaN);
//=> true
numberIsNan('unicorn');
//=> false
MIT Sindre Sorhus