prime factoring, oddly enough, is simply dividing by primes, anyhow, without much adieu.
36 = 2 * 2 * 3 * 3.
but anyway, prime factoring, is dividing by first 2, till you can't, then 3 till you can't, then 5 till you can't, and so on, and that plucks out all possible factors on any number.