List of recent champions for factoring Cunningham numbers: Special number field sieve by size of number factored: 6297 C355 2,1193- J.Bos+T.Kleinjung+A.K.Lenstra 6315 C342 2,1171- J.Bos+T.Kleinjung+A.K.Lenstra Special number field sieve by SNFS difficulty: 6297 C355 2,1193- J.Bos+T.Kleinjung+A.K.Lenstra 6315 C342 2,1171- J.Bos+T.Kleinjung+A.K.Lenstra General number field sieve by size of number factored: 6665 C221 2,2246M NFS@Home+mersenneforum 6319 C221 3,697+ NFS@Home Elliptic curve method: 6208 P83 7,337+ R. Propper 6135 P79 11,306+ S. Wagstaff Largest penultimate prime factor (ultimate factor shown also): 6630 p151*p160 7,889M NFS@Home 6537 p147*p156 12,293+ NFS@Home First five holes in each table on November 7, 2023 2,1207- c337 2,1213- c297 2,1217- c248 2,1229- c284 2,1231- c329 2,1123+ c338 2,1129+ c330 2,1139+ c248 2,1147+ c317 2,1151+ c236 2,2266L c255 2,2302L c293 2,2306L c287 2,2318M c296 2,2342M c291 2,1124+ c311 2,1168+ c326 2,1208+ c330 2,1216+ c263 2,1240+ c216 3,691- c265 3,703- c269 3,715- c211 3,725- c217 3,731- c265 3,692+ c277 3,701+ c302 3,709+ c327 3,712+ c330 3,716+ c264 5,503- c260 5,509- c271 5,521- c364 5,529- c281 5,533- c336 5,467+ c230 5,472+ c317 5,478+ c311 5,479+ c224 5,488+ c301 6,421- c281 6,431- c321 6,437- c273 6,439- c293 6,445- c259 6,421+ c246 6,431+ c331 6,436+ c258 6,439+ c270 6,443+ c282 7,389- c299 7,395- c220 7,419- c214 7,421- c305 7,425- c221 7,388+ c314 7,395+ c221 7,397+ c300 7,398+ c332 7,401+ c260 10,353- c328 10,365- c288 10,377- c311 10,383- c230 10,389- c270 10,332+ c295 10,346+ c300 10,347+ c318 10,353+ c300 10,356+ c292 11,317- c319 11,331- c344 11,341- c289 11,349- c294 11,359- c352 11,326+ c334 11,328+ c242 11,331+ c258 11,332+ c282 11,334+ c219 12,311- c335 12,313- c283 12,319- c260 12,331- c290 12,337- c265 12,307+ c304 12,326+ c347 12,328+ c301 12,331+ c241 12,332+ c289