Challenge Numbers to factor

544303641316172369346936026952485747650577308864401791793284120939582508471909798963143756326812287602439664069511  (spring 2006)
526354155328127706425535221621969825511979071414194091112059861906097043494433208148548494372443  (spring 2005)
932239342869667223652571524895075332158491080855838499929 (spring 2004)
 466436659259931613515276793012374771149972389002941693309
241975308641975308641995700246913580246913580596997
822738556506321687397
738556506321687397
817143663911 
examples:

6919249991708261594945147738006832038291

factors:

1029647382110731
6720019020030050607012761 time: real 19:00.32 minutes code: brent.c

354984745389040574704783809843747384387511111
A factor is 53 found on 4-16-96 using the elliptic curve
method. Programmed by Supannika Rongsopa. 

some factoring methods
RSA challenge numbers 

links to 'prime' sites