(function (exports) {

'use strict';

/**

* Advanced (optimised) method for checking if provided number is prime.

* For example for number 104743 it should return true, for 104744 - false.

*

* @module primes/is-prime

* @param {Number} number - Number that we check on prime.

* @returns {Boolean} Will return true if provided number is prime.

*

* @example

* var isPrime = require('path-to-algorithms/src/is-prime').isPrime;

*

* console.log(isPrime(7)); // true

* console.log(isPrime(18)); // false

*/

exports.isPrime = function (number) {

if (number < 2) {

return false;

}

if (number % 2 === 0) {

return (number === 2);

}

if (number % 3 === 0) {

return (number === 3);

}

var horizon = Math.floor(Math.sqrt(number));

var factor = 5;

while (factor <= horizon) {

if (number % factor === 0) {

return false;

}

if (number % (factor + 2) === 0) {

return false;

}

factor += 6;

}

return true;

};

}(typeof exports === 'undefined' ? window : exports));