Primality Certificate for (8921^3049-1)/8920

Andy Steward12,041 digits14 June 2007
Originally by A.A.D.Steward 2007

This certificate uses a theorem of Brillhart, Lehmer and Selfridge to prove an integer N prime by making use of a partial prime factorization of N-1.

Factorizing N-1

As N is a Generalized Repunit, we make use of the algebraic factorization of N-1 to arrive at the following 34.982482% factorization of N-1:

From Factorisation
892111 · 811
Φ22 · 3 · 1487
Φ313 · 2143 · 2857
Φ42 · 17 · 17 · 157 · 877
Φ63 · 7 · 307 · 12343
Φ82 · 193 · 857 · 19146351641
Φ12241 · 1009 · 6553 · 3974713
Φ24p32
Φ1272939587578489743 · c483
Φ254509 · 2541826769 · c486
Φ381829146641238696335557 · c975
Φ5081133857 · 13071857 · 198473272344001 · c969
Φ7622287 · 9907 · 271586138311 · c977
Φ1016563564701386813881 · 23631425893010311913 · c1954
Φ15243049 · c1988
Φ304858545834891958873 · p3966

From this partial factorization, we use sufficient of the largest prime factors of N-1 so that their product F is at least N 1/3 :

177562 6756589274 6132254357 8059634387 0106864127 4736310617 1699668351 6552776575 1782103572 2074558347 5097238487 1665516926 8186283693 3150402358 1400786899 7288954678 7791513327 9231987361 4354962757 6381119077 3284294615 0809771510 3946094092 9230354247 6033585366 0763184559 3556274270 5360537402 5152079620 3629146323 2053169674 2446259853 3102761890 9076147992 5031454239 4755198739 4818315303 5492265569 9654253358 0026951868 4224879430 5825368596 8210128155 1798831520 5912519020 4992866450 1339922110 4805296115 9269071042 3505642433 4810839437 6085226106 8310718363 3453095293 9788363805 2031978814 0056586620 2161247684 0655207504 4697817166 0522748217 0268888202 0552070986 7058163372 9202730027 9169722537 1652644616 1607508190 0576152482 1952706072 5962241158 2625803112 1231323178 5803888289 7084264108 1532444224 6752435943 1435456722 1891997255 0381394749 3917509286 6870565769 6363307987 9070516913 7083885059 9757263286 0431475556 0265594481 3480003981 1849545859 6463911842 8497821271 4642038781 0924841163 2589406406 0567820984 3055594245 6924553029 1170967186 4946651316 4288224569 0947536726 2342258763 2687728647 9390609308 2297865544 1402796070 7892825561 6847775157 5788381559 8036528485 3639570552 7051727614 6140325760 8556747768 6741030101 3298174966 5365591199 8575533883 3433983245 5787608855 8538811586 8983567185 2594971063 9154803112 7431550760 1747785473 6885903020 7446109338 6471964297 3070717252 0001834086 9037621252 7955768034 7711372105 8969902877 1384871064 8804345555 6434278115 3743080449 1926401826 3865523067 2737285963 0488741304 9761951097 6873848640 7381832275 4977158992 3376736838 3029349742 9442395161 1190746392 4594736841 7870298462 3937788759 8582561045 8404294341 0888397502 9877261746 9023710915 9981866718 6410316899 0245355370 5571602806 8825513138 1080586793 5423933644 5586899488 9889412961 1057361263 4596130857 8885789258 2342284366 9529046924 1345253357 3138480829 3121263112 6209339657 2298916995 0347047247 0564265248 8931285267 9520279652 7404188868 2889887043 9420764028 9214808996 0482476966 7745246697 0159813648 2048935981 0264670485 0066961996 5899238091 8807899927 9379792362 3354252729 4081789273 1322971648 5169334477 5594196444 2143767049 3677216846 3428699206 8410912717 5104308870 2839028328 9668457103 8704728303 0482408636 2161011346 5228810114 0564457111 7384655444 4830527145 5194259316 9139547872 3671358525 1151089226 3930362972 6779686051 4819013014 9583730248 1885627183 7857344533 4798154054 6882568977 9429688194 4967538162 4778494414 8864555248 7634689958 0563065910 6700117488 8196807840 3382896357 3491740541 2309518321 1636412169 6842172634 3282214518 9692795645 1412509852 2255289180 5555187418 8940851582 4615787538 2064147647 9101754333 1586212866 5735644293 6111516090 4428680520 8697780661 5891069924 4017182070 7365240635 4835305799 1010889001 6100267453 7201077629 2959270686 9607768991 8745113235 8671352138 5725273664 3822909061 2392941242 9694146725 5757418158 0344735619 8448770771 2471766596 4105450544 4458132480 9727105266 7513744072 0155051393 3353169645 4503443515 5621671298 7436902780 2113881196 0225674307 9305348230 1817445436 2369138229 2641337024 2408541767 7916946033 9387868304 8980673885 6336553234 8759122855 5035172004 6040958844 2990757517 7121504745 1370735998 1258550320 8695622442 4584138116 9154090215 7206809148 4012567305 4133141571 3138339947 7193399369 7628395344 3737720667 1904992451 1433193423 7166093603 6592003279 8129377325 7466852722 2159383110 7960653613 3426159625 9581217129 9824896835 4934669010 2268579981 8435729161 7704128914 9173343495 4951476249 4015683781 9614105212 6830467376 4731636931 2419445414 8831421979 9899022354 3786300740 8727373622 1984652838 7022688872 1368882089 4321804909 5024968887 2894631965 1297948128 3196461902 1654365208 2733863885 3843290971 8830958325 5709839933 1998955300 0531425215 2050419711 2886009624 4066998232 0864279526 9192482260 1772511905 3856053024 4551478515 7059971014 9590334344 3756097450 2189793182 1235643204 7050792345 4117932802 1408313881 5031524028 8124277468 0089863603 7344208917 8180869969 1800640340 6820383129 3143838021 4454735423 5480509973 0577398879 6987066463 7646130389 9564793385 3732072841 7515949897 2719770569 2615009152 3798143435 3101609397 0943117877 1325204506 3722112816 8924551971 4037628458 4038380758 7622762263 6504306186 8593672700 7792800297
40 1151402536 4886928835 6018912481
8 2914664123 8696335557

Note that all prime factors listed above have been proven. As primes of under 250 decimal digits can be verified in a few seconds, proof of their primality is not included here, in order to save space. Larger prime factors can take from hours to months to prove; certificates for all such factors have been PKZIPped into this file.

We set R = (N-1)/F. Note that GCD(F,R)=1 and Log(F)/Log(N) = 33.367809%

Finding a Witness to Primality

Next, we find an integer witness w such that for each prime factor p of N-1, w(N-1) ≡ 1 mod N and GCD(w(N-1)/p-1,N) = 1. In this case, w = 19 suffices.

Given such a witness, Pocklington's Theorem shows that every prime factor of N ≡ 1 (mod F). As F2>N, N can have no more than two prime factors.

Express N in base F

As F2 < N < F3 and N ≡ 1 (mod F), we can let N = c2·F2 + c1·F + 1.

Brillhart, Lehmer and Selfridge

Brillhart, Lehmer and Selfridge's Theorem shows that N is prime if and only if c12-4·c2 is not a square (given 2F3 > N).

Here, c12-4·c2 is ≡ 13 (mod 64) and therefore cannot be a square and N is prime.