12's factors are: {1,2,3,4,6,12}
function factors (n) { let list = []; for (let i = 1; i < Math.sqrt(n); i++) { if (n % i === 0) { list.push(i); if (i !== Math.sqrt(n)) { list.push(n / i); } } } return list; } factors(12) // [ 1, 12, 2, 6, 3, 4 ]