Returns the Factors of N
Factors: Numbers which multiplied by another number go into the target.
e.g. 12 (1 x 12), (2 x 6), (3 x 4) = 12
1,12,2,6,3,4 are factors of 12

; Usage: $factors(N).P
; 'P' above can be: List (List factors) || group (factors grouped like (F,F)) || num (Number of factors)
; Example I: $factors(2).list <--- Returns 1 2
; Example II: $factors(15).group <--- Returns (1,15) (3,5)
; Example III: $factors(372).num <--- Returns 12

I searched around and couldn't find an in-built function for this (I hope there isn't one now I've made it!)

; Usage: $factors(N).P
; 'P' above can be: List (List factors) || group (factors grouped like (F,F)) || num (Number of factors)
; Example I: $factors(2).list  <--- Returns 1 2
; Example II: $factors(15).group <--- Returns (1,15) (3,5)
; Example III: $factors(372).num <--- Returns 12
alias factors {
  if ($isid) {
    var %x 0 | var %t
    while (%x < $calc($1 / 2)) {
      inc %x
      if ( . !isin $calc($1 / %x %y)) {
        if (($prop == list) || ($prop == num)) $iif(%x isin %t,,set %t %t %x $calc($1 / %x))
        elseif ($prop == group) $iif(%x isin %t,,set %t %t ( $+ %x $+ , $+  $calc($1 / %x) $+ ))
      }
    }
    if ($prop = num) set %t $numtok(%t,32)
    var %y %t | unset %t
    return %y
  }
}