#!/usr/bin/perl
use warnings;
use strict;
########

my $doSqrt; if($ARGV[0] eq '--sqrt') {$doSqrt = shift @ARGV;}   # added to toggle whether or not I do the sqrt after ever num

sub prime_factors {
    my $num = shift;
    my @primes = ();
    my $max = sqrt($num);
    while ($num % 2 == 0) {
        push @primes, 2;
        $num /= 2;
    }

    foreach (my $i = 3; $i <= $max; $i += 2) {
        if ($num % $i == 0) {
            push @primes, $i;
            $num /= $i;
            $max = sqrt($num) if $doSqrt;  # added by [pryrt]
            redo;               # changed from [id://1194102], where it used to be:     next;
        }
     }

     if ($num > 2) {
        push @primes, $num;
     }

     return @primes;
}

foreach my $n ( @ARGV ? @ARGV : (20, 48, 96, 7, 69, 33, 13195,  600851475143, 2147483647) ) {
    my @result = prime_factors($n);
    print "Number: $n , Prime_Factors: => @result", "\n";
}