Primality Certificate for (6556^2053-1)/6555

Andy Steward7,832 digits19 September 2005
Originally by A.A.D.Steward 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 41.518585% factorization of N-1:

From Factorisation
65562 · 2 · 11 · 149
Φ279 · 83
Φ33 · 7 · 619 · 3307
Φ41301 · 33037
Φ613 · 211 · 15667
Φ93 · 37 · 109 · 3061 · 2143980658162207
Φ1261 · 30284885391301
Φ182089 · 4969 · 7649379941151601
Φ1919 · 647 · 7639 · 54942972563 · p50
Φ273 · 163 · 18199 · 1229463502945473007 · p44
Φ36159589 · 6363457453 · 27428986693 · 226340086165471860301
Φ3818218575388174629736202479086768301 · p35
Φ541505008103483710730111887 · p45
Φ57229 · c136
Φ767624710109 · 72923999735072461 · c111
Φ108c138
Φ114156073069 · p130
Φ171c413
Φ228457 · 27817 · 310822380541 · 6114500927633653 · 445666621457105401 · c223
Φ342318472770061 · 30227327221790644417 · c382
Φ513897751 · 13035331 · 8852948250859 · 33683255318197 · c1198
Φ6844789 · 6841 · 613549 · 31582333 · 24667939585441 · c791
Φ102611287 · 807463 · 3179489869 · 33184607473 · 10224870157063 · c1194
Φ20522053 · 4067462089 · 2868418959481 · p2448

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 :

63486479 7547390504 2736438977 9958971398 9860703033 5304203878 0595060415 9401385630 3860204867 4051892836 3545123680 8430675548 6492147427 2768343294 9225106529 8856467325 8384445655 6840092564 7607778064 8518909192 2076154388 3616146096 4990940845 1082629403 3342078771 5766054172 6608912602 9393147448 1354980289 8357627877 1974089211 9490681653 1766154368 2616184430 1653183694 3868422958 3625065380 6298245735 4407779581 0256982806 0084807013 5429152199 9428689496 3829840058 4946076110 6800903192 2405274775 1434579175 3024883048 6414853931 3053606190 6723385125 8701141663 8065118159 7243569889 0670831814 9111286908 2032703482 6286014602 6303018090 7975235138 8009625948 7913682023 3507019346 7628606849 2111847392 7675597215 6908301314 2790375196 9711985164 3256318682 2247221214 1891491086 1236169067 9369804928 8781781767 7773570386 9148433396 3248425784 8750944050 5940863145 3412972045 1943034696 8558295434 9747304786 3173471482 7692630102 9884133782 1623833276 6277637963 8240016521 1287054060 6817800337 7156314013 8859184896 2349722285 2891572617 7880399264 1649340728 4272070584 1956746941 4762751411 4941771043 6177179482 8841261357 6083217141 3659460315 4329955177 8120149407 8765386134 2760752588 0443938511 3420034936 1143844109 9254416112 9871193968 2504822948 8032519792 6949175726 1646104958 3626957322 7724121768 0440807097 2509290491 9000590630 5904996431 0409092675 9009860136 3527995423 0171269057 9603373916 4648410605 4502661467 7838220466 7483323561 3254105158 8950837232 7866152526 4580747739 2642345852 9656851965 1231830000 1740068501 1629248829 8520751901 3023572250 6206887226 8882587860 8091751564 4973482402 8172821040 4592908951 0055556889 4435296501 7554332492 6887214997 1404255173 2169727721 2505905139 2008640480 7908521128 8540507761 9029392755 9353028921 0609166930 9279660245 3946705166 1523234940 1186457855 1169734596 5131898418 7936834035 8093305608 3361537005 5867149263 2971591178 2575193560 6423722873 9847058961 5635794275 4249113759 7986890115 0782325905 8764055249 5909426782 5273158622 3880631280 2626832172 9420368967 2551792422 8928870303 1040449272 4250118757 6880329773 5108941039 2731800135 2940401024 1998823829 2141130062 5493077303 8507141416 1284499565 6723914230 6135038590 1646912091 8191372641 9641146315 5849642863 0282182422 9830350784 5872768832 6045193795 7607879709 7266521426 0755678750 4442549273 9505652702 6617670775 3182234016 1228751469 3253916600 2564914124 7611731736 8108757816 3131483722 1022445551 1297774304 6208054245 6354097122 9278626091 9817283153 4041192561 5132361871 1518705026 3264683727 3021769243 4631846032 8499639013 8410105193 6024367193 9993692713 6701402733 4092471786 2399680337 4331028173
1605980562 9488747131 9844987683 7030208122 9538328948 8038807298 9311149963 7259141160 1374922722 2279545380 9429397863 2402708879 5173962289
9704221776 5857129245 1038864011 2033537410 9117138949

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) = 33.542920%

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.

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's Theorem shows that N is prime if and only if c12-4·c2 is not a square.

Here, c12-4·c2 is ≡ 21 (mod 64) and therefore cannot be a square and N is prime.