pub fn squarefree_primes(m: u64) -> Option<Vec<u64>>Expand description
The distinct prime factors of m, in increasing order — or None if m < 2 or m is not
squarefree (some p² | m). Squarefreeness is exactly the condition under which ℤ/m is a product
of fields, so the CRT-over-prime-fields decision procedure below is complete.