Factorise integers. Use the list of factors to find highest and lowest common denominators

factorise.ts

function factors(x: number): number[] {
  const f = [];
  for(let i = 2; (i*i) <= x; i++) {
    if(x % i === 0) {
      f.push(i);
    }
  }
  return f;
}
                                                   
function lowComDom(x: number, y: number): number {
  const xF: number[] = factors(x);
  const yF: number[] = factors(y);

  return xF.find( i => yF.indexOf(i) >= 0)
}
    
function highComDom(x: number, y: number): number {
  const xF: number[] = factors(x);
  const yF: number[] = factors(y);

  return xF.reverse()find( i => yF.indexOf(i) >= 0);
}