I'm happy with what I have, whatever it is. Check this ( with cygwin ):
$ time factor 431238384397394731494949493865668771 431238384397394731494949493865668771: 22175407456858039 19446694958654684789
real 5m47.188s
user 5m47.071s
sys 0m0.046s
Amazing! Incredible! Beyond MY wildest imagination, I can assure you.
Sigh. How about:
$ time factor 431238384397394731494949493865668771
431238384397394731494949493865668771: 22175407456858039 19446694958654684789
real 5m47.188s
user 5m47.071s
sys 0m0.046s
( The preview took a “natural” line break after the argument of “factor”. )