Amazingly, following “don’t repeat yourself” in its purest form, is-even depends on is-odd:

  /*!
   * is-even <https://github.com/jonschlinkert/is-even>
   *
   * Copyright (c) 2015, 2017, Jon Schlinkert.
   * Released under the MIT License.
   */

  'use strict';
  
  var isOdd = require('is-odd');
  
  module.exports = function isEven(i) {
    return !isOdd(i);
  };