This is just a toy to factor some integers. The source code is available for your amusement. This runs on a very slow machine and may take a long time to return your answers. Prime numbers will take the longest. If a number has small prime factors, it will take less time than if it has at least one large prime factor. For example, 123456789012345678901234567890 has 2906161 as its largest prime factor and takes about 5 seconds to factor if the machine is not busy. 1234567890123456789012345678901234567890 takes almost 3 minutes of CPU time.
Last modified July 2, 1996 by John Moyer.