Project Euler Крупнейшая ошибка Prime Factor в Javascript

function largestPrimeFactor(num) {
  var primeFactors = [];
  for (var i = 2; i < num; i++) {
    // check if iter i is prime
    if (checkIfPrime(i)) {
      // if so, see if its a factor of num
      while (num % i === 0) {
        num /= i;
        primeFactors.push(i);
        console.log(primeFactors);
        console.log(num);
      }
    }
    if (num === 1) {
      // return Math.max.apply(Math, primeFactors) 
      console.log(primeFactors);
      console.log(Math.max.apply(Math, primeFactors));
    }
  }
}

function checkIfPrime(num) {
  for (var i = 2; i < num; i++) {
    if (num % i === 0) {
      return false;
    }
  }
  return true;
}

console.log(largestPrimeFactor(13195));