#! /usr/bin/perl
use Math::Pari qw(:int factorint);
print factorint($_), "\n" for @ARGV;
[download]

bash-2.01$ ./factor 491320487930121938479123 4839013210437894323
[48049,1;10225405064207828227,1]
[11,2;36809477,1;1086455119,1]
[download]

It does have to think, though, about:

bash-2.01$ ./factor 4913204879301219384791234839013210437894323
[3,1;19,1;82471,1;17992995173,1;4100172797059,1;14167170962387,1]
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sub f {
  (1x(my$n=$_[0]))=~/(1+)\1+$/;my$p=$+[1];$p>1?(f($n/$p),f($p)):$n
}
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   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

This code produces the wrong answer for 366178. It gives the prime factors for 366180.

i have only PII350Mhz with 128 RAM... i just want the code for fun... (and to crush my computer down...)

Ah, well then, I don't know if my code helps with the former, but for the latter, I heartily recommend one of these.

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

  my $n = shift or die;
  while( $n % 2 == 0 ){
      print "2\n";
      $n /= 2;
  }
  for( $_ = 3; $_ <= (my $sqrt || sqrt($n)); $_+= 2 ){
      while( $n % $_ == 0 ){
         print "$_\n";
          $n /= $_;
      }
  }
  print "$n\n" if $n > 1
[download]

_____________________________________________________
Jeff japhy Pinyan: Perl, regex, and perl hacker.
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;

Sorry, I'm not very good at factoring in decimal but you can always convert to base 1: prime factorization using base 1 ;)