/* The prime factors of 13195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600851475143 ? */

primeFactor

/*
The prime factors of 13195 are 5, 7, 13 and 29.

What is the largest prime factor of the 
number 600851475143 ?
*/
function getPrime(n){
var aPrimes = [], max = 0;
  function primeTest(d){
    //test the divisor to see if it's prime
    for ( var i = 2; i <= Math.floor(Math.sqrt(d)); i++ ) {
      //if it's divisible it isn't prime
      if( d % i === 0 ){  
        return false;
      }    
    }
    return true;
  }
   //check numbers until sqrt of n
  for ( var i = 2; i <= Math.floor(Math.sqrt(n)); i++ ) {
      //if it divides the n test it for primability
      if( n % i === 0 ){  
        //if it is a prime save it
        if(primeTest(i)){ aPrimes.push(i) }
      }      
  };
  console.log( aPrimes );
  max = Math.max.apply(null, aPrimes );
  return max; 
}