1
2function primeFactors(n){
3  var factors = [], 
4      divisor = 2;
5  
6  while(n>2){
7    if(n % divisor == 0){
8       factors.push(divisor); 
9       n= n/ divisor;
10    }
11    else{
12      divisor++;
13    }     
14  }
15  return factors;
16}
17
18> primeFactors(69);
19  = [3, 23]
20        

1public List<Integer> factorsOf(int n) {
2  ArrayList<Integer> factors = new ArrayList<>();
3
4  for (int d = 2; n > 1; d++)
5    for (; n % d == 0; n /= d)
6      factors.add(d);
7
8  return factors;
9}
10