Primality testing gcd(V(52825),5*F(52825/5)*(F(52825/5)-1)+1) [N-1, Brillhart-Lehmer-Selfridge] Calling Brillhart-Lehmer-Selfridge with factored part 30.13% gcd(V(52825),5*F(52825/5)*(F(52825/5)-1)+1) is PRP! helper: << 2 5 5 13 641 1049 1087 1447 2113 4481 5737 35201 141961 2563969 75440641 75518783 683478401 1435815041 5072305921 11862575248703 42311526823103 5326379933318401 31187396775005101 35323750923943681 499750037222722721 8132307034170126721 3891324187650256896001 878132240443974874201601 2211745416606187093767661 1271150843287904563935054721 2811666624525811646469915877 471991644996070811213117005172115579281 1931734634522754726108707718410439174358483201 316837008400107576629115441641182686718784605974069121 717183675566658213132761730294626635650067479275923957352582406983301023453681347576121 1294884906033467167459275761658328869257948204777663121266918228225397498956629185213102721 4803658436325482520297638915610297327172500447085995837685448718393398021102387961508954460708151467171902227193383138649187081613761988158080851197141142687882714108512807667903716826727900953898257678338906293184183179605112525027159635875754366834111281530688122982068596616838092252817393837440415681649405023438489552891309442925601951853249448297320649244311189113417746777090338754586530687736559414352447922013221225094130264219311765429963842465899423437961862094906911217635020275701152671009954306655852270877554286118548877950785037990297343654313453616722792209319752996500195729949295106481009045526160574181325480600881237205398590084938129926524688840773271110628749178344879721 >> with prime factors of N-1 proven by PFGW and Primo. Then we used Konyagin-Pomerance, since we have more than 30% of N-1.