Primality Certificate for (2153^3877-1)/2152

Andy Steward12,919 digits06 May 2008
Originally by Tom Wu 2005

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 40.257103% factorization of N-1:

From Factorisation
21532153
Φ22 · 3 · 359
Φ37 · 241 · 2749
Φ42 · 5 · 13 · 181 · 197
Φ63 · 523 · 2953
Φ1221487011961873
Φ17103 · 113153 · 260543 · p41
Φ19191 · 18773 · 76913 · 162413 · 2385451 · 9728039 · 489840916867669 · 1941582504686789
Φ341631643919 · 4856701373 · p35
Φ38571 · 4751 · 21902479 · p47
Φ51307 · 22355450314724001043 · p85
Φ5717685163 · 31181871433 · 129729632187670087579 · 14452871940069278131535671 · p57
Φ68137 · 11138099593347413 · p89
Φ7688933301 · 2577561120097 · 39980813208180841 · p84
Φ102919 · 9365859456469 · 20778159325121127575479 · 10070467131767763070047244065999589 · p35
Φ11456431 · c116
Φ204409 · 9181 · 16010074021 · p197
Φ228229 · 12541 · 157827757 · 9559558180444837 · 180140758335193131035592371591353 · p178
Φ323647 · 72353 · 1254326384783387 · c938
Φ646c960
Φ9697753 · 6899281 · 107161131605839 · c1896
Φ1292905693 · 697121857 · c1906
Φ193813567 · 9984159331 · c1906
Φ38763877 · 8773841509 · 871963914352258190269 · p3806

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 :

156508 5848661701 8150580076 6490803860 0452082952 6759818258 1040774984 2685754258 6613415690 1669069992 5264069385 6506621664 8672441005 4030664017 9442794217 1894258890 5022275428 9651213419 5300353738 6974014049 2564409585 4129223562 0537909754 9251849227 6364699661 8360055148 0069694360 8840999756 7731619361 7801451951 9235875431 8886634180 9300762599 9213052343 5152004043 8661632875 3932941797 8558532135 2677711783 3481278731 6829757761 8502122914 1800266901 5715616706 7237507579 2072074005 3262368199 1881653527 1134590813 3205712016 5154996054 4782336242 8850097991 0382340896 4937858276 3742573290 1797077040 7561047941 5152310349 8894802524 0483541976 8250443471 5716115837 9905467207 9391533127 2846756320 3073139062 4168737783 9955301972 5413712255 4852932263 4834819194 1122956468 0068185202 2265011047 5589439475 4436029285 6083380928 5346146035 9093155138 3600667496 8672241629 4748720430 9754906602 4151449732 8854029252 3673962225 9469808939 3942274336 7209835052 3967714778 5445030561 4261646347 8994321980 7226926449 8037349163 5673132228 6231855150 4148336208 6483245113 6397535965 6885495601 4870967137 7561133327 3881069971 1676606175 6890191914 1200215637 0923474346 3175376976 3675348171 4200722621 4059078516 5576452404 5075320291 0605176849 4389382234 6631571516 8999537807 5637626808 8688072684 7850109551 6286417349 6842896073 2977061145 9626628654 7128941728 0572336542 9800538920 4351112052 0062612452 1427074624 4669705837 8094734667 2525918216 9326432275 4776065853 0572070426 6363399823 5426391598 1430866513 4223281447 2812340279 4168119856 7920747877 0084808642 1769617318 7667404037 4417584720 3050381404 3167458843 5628460810 3358650378 2025148621 4374973961 1628884541 4386056378 1620872809 7844723533 2182753535 1198529317 8686217812 5851196444 9959332318 1001795734 6075981337 5772933444 3678406359 1504762155 5900680923 3463139437 7680832382 5818418251 1279558976 3415466042 6577801531 0990116849 1710329530 8435854234 9042209473 5308968566 7763052055 8037889128 7198671550 1532138142 9814877187 3636092272 8208731203 2978045350 8791463456 7375808442 5909195061 4535061151 7683660419 4820779176 6671530434 3209345745 2736022618 9512031993 0681037413 3623056995 6750201095 6415053618 4458671492 8062983178 4809552867 9506111505 2778445846 6484934327 9596296661 0081365780 1563024420 6497725609 5664687348 0543422962 9237809756 2536346205 8219524004 7869375194 7547383454 3868601216 4712965907 7589697843 2540807712 9239743038 2471067486 3691616271 3650475048 4803069419 4321262982 1162163460 7144175162 3004900668 1227621241 4086295766 9052067066 5269609862 5864480224 6909448118 9586083299 6552398435 4153001621 6621077471 7189391293 1242459726 0352871388 1419568393 0276120012 8932174163 3197173670 7800367762 5340014171 6453054471 7881222697 7641432989 5163824985 8215098457 1147405035 3705223828 9393376258 0152894515 5749940926 3317591374 9386828068 6523333656 6088639167 6937171176 8195995785 6559588853 8904968591 4227955546 4390473281 0937418006 2544557987 2717042145 6808404271 2752527441 4084374295 5298793413 2149006323 4811636017 9355201723 7578566067 9613578362 6572909487 0880798176 3517500035 7803920736 4467342544 9397872535 9923872779 5843326123 5313294307 4456678916 4674984799 5095590849 7510196148 5216845521 2440934199 1399381316 4585174366 7891989236 2390325575 5131092092 1479088317 6909807456 8386975655 0230732632 4655928296 3791951278 2164817141 4496953439 4039057906 1435827093 6057762700 3447963221 3748621005 8921743774 4953222532 8061161594 4081687823 7973762765 2206775482 0645871679 7922794590 1718530911 4651213055 1376390417 4912046194 3619829175 0717927403 9781355402 8291504597 2600314515 3105126729 3408580521 0831290926 7909483982 9457922034 1214403318 4674143676 3457552891 3344528343 7223736481 4123964132 9886082944 5102872969 8845199485 5904682577 0362460572 6553409104 9828695502 0086063454 9134711424 9500696111 8997284129 4655000407 3053676052 4473542345 9775037606 8429212994 5883502980 0313426911 8229811079 9969208372 0869066155 5168136122 2218430438 2470370065 4421592026 1714308933 3369250203 3675237888 7239172816 6024533722 8126453815 4296610246 7210106565 4290345916 7661025151 5205733213
3434087 5824983024 4576539304 0512145405 7933427893 5552478982 2981737455 9009433063 1928505612 1199410938 4736787903 7898986544 2863626509 0878202003 8057958133 4665846421 7165903980 2058236803 8209422117 0562353849
12211510 8293480986 6638206338 3118124944 2203213832 4049635924 2847631729 8434069063 6720424351 7052015903 2247393344 6372980210 6252101254 0015831614 3691389696 1550321416 7746795293 4553280857
297767432 7536392893 2901019042 2856616577 8490550907 8424998879 8645453561 0339475434 1695558997
66173 6962522988 0257330932 4494763514 5083990728 4674848688 1010493679 4900021751 1383022841

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) = 33.687998%

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 = 2 suffices.

Given such a witness, Pocklington's Theorem shows that every prime factor of N ≡ 1 (mod F). As F3>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 ≡ 48 (mod 64) and therefore cannot be a square and N is prime.