RSA-640
RSA-640 has 640 bits (193 decimal digits). A cash prize of US$20,000 was offered by RSA Security for a successful factorization. On November 2, 2005, F. Bahr, M. Boehm, J. Franke and T. Kleinjung of the German Federal Office for Information Security announced that they had factorized the number using GNFS as follows:
RSA-640 = 31074182404900437213507500358885679300373460228427275457 20161948823206440518081504556346829671723286782437916272 83803341547107310850191954852900733772482278352574238645 4014691736602477652346609 RSA-640 = 16347336458092538484431338838650908598417836700330923121 81110852389333100104508151212118167511579 × 19008712816648221131268515739354139754718967899685154936 66638539088027103802104498957191261465571The computation took 5 months on 80 2.2 GHz AMD Opteron CPUs.
The slightly larger RSA-200 was factored in May 2005 by the same team.
Read more about this topic: RSA Numbers