Factorize integer using awk

factorize.awk

# awk -f factorize.awk
{
  n = int($1)
  m = n = (n>=2) ? n: 2
  factors = ""
  for (k = 2; (m > 1) && (k^2 <= n); )
  {
    if (int(m % k) != 0)
    {
      k++
      continue
    }
    m /= k
    factors = (factors == "") ? ("" k) : (factors " * " k)
  }
  if ((1 < m) && (m < n))
    factors = factors " * " m
  print n, (factors == "") ? "is prime" : ("= " factors)
}