export function getFactors(num: number) {
  const isEven = num % 2 === 0;
  const max = Math.sqrt(num);
  const inc = isEven ? 1 : 2;
  let factors = [1, num];

  for (let curFactor = isEven ? 2 : 3; curFactor <= max; curFactor += inc) {
    if (num % curFactor !== 0) continue;
    factors.push(curFactor);
    let compliment = num / curFactor;
    if (compliment !== curFactor) factors.push(compliment);
  }

  return factors;
}