Primality Certificate for (2130^2539-1)/2129

Andy Steward8,448 digits14 October 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 41.341771% factorization of N-1:

From Factorisation
21302 · 3 · 5 · 71
Φ22131
Φ37 · 648433
Φ64534771
Φ969193 · 1073647 · 1257054031
Φ1819 · 37 · 4177 · 31802248024471
Φ272269 · 1350487 · 5252918278118583208879 · 50594966618172870331140196573
Φ47941 · 2633 · 502770874363 · 776013762796959581509 · c115
Φ54541 · 1567 · 11503 · 1087531050871 · p38
Φ94283 · 4231 · 4889 · 17203 · p140
Φ1416658665755571751 · p291
Φ28221997 · c302
Φ423145063621 · 5762292967 · 2271278788201 · c889
Φ8461693 · 378163 · 32426242633 · c900
Φ126927919 · c2752
Φ25382539 · 5077 · 67729069 · 8395275079 · 3006042450939343 · p2716

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 :

359117 5561991335 5283636037 2315983165 3121118968 5204096228 0110427861 4630513139 9335161671 9892288044 7792142522 5009702495 2003008628 8077176414 9487839015 8148732697 7384035831 2978737338 8985943629 6464310661 8758177679 0978677624 8116875211 0388071685 7513823940 3355693359 5963465074 6464609112 2636885570 2757499170 3307644752 0267821929 9492001322 5251774598 5166808226 0953381319 5258861233 9298410842 1645899157 1979087757 1796670398 0823731240 8750188229 2774271554 5771981586 6781879131 3717063032 9364193130 7230653080 8934491160 8054947251 4042840138 1387577994 4432987062 2535732004 0795357927 4048255331 9878144675 1721873057 6212299255 7539260614 3552258208 4376313167 6918933882 1163733417 0953843606 4371328789 2376172287 8305029976 1097297562 0661602410 8089461865 8740440507 2780130380 6045562758 8626305258 4885291206 3036497134 3939518198 3067867421 6001608902 4018256341 8354223754 9162541223 7417918438 9070328533 6210193438 5654595225 3092496020 9345170860 9571694163 6384064017 6391040122 4646026923 7635372089 7741018157 4201824323 2115120889 0087005055 8596244715 0100997779 4680756061 7258827881 8058925532 5149749830 0619902101 3841634984 4647014066 6299054275 1803076864 2176558741 2428557232 5266782185 6872859007 7764457391 4637451901 4168742183 4429607087 6003589490 2535342631 9532096174 6445449231 7976202307 7179890980 0707211861 5685154679 0921562540 4177375008 5940102641 4114736324 2727459070 9001381090 8032143309 8467507766 4150061272 0799862810 7671511132 5282919449 1217164489 5945707173 4617359835 3604569525 3777926430 5278705493 2499788085 7891080383 3018702604 1269667937 3196389031 2891530089 0770999232 2240459250 7248124602 3817739320 5325714068 1718436711 9070708397 2532084606 8181748072 8980031014 9496843231 7157661534 8294350858 9126114235 3773214182 6951303842 0048608174 5976046771 6797254170 3453129029 1506208655 3970935605 4901257138 8609023154 7328349978 0278364732 2039863007 5548565852 3936153585 6180642450 5290373677 1784252569 0947011886 6058708562 0509339070 8330636995 8256951047 2547140461 1934229653 0788598307 4822535136 0760146053 4873191133 5714229283 0882018559 0389945396 4100038690 4197882279 0958881481 7888451979 2568387086 8982694244 4082219778 1931357782 4211990618 7674146032 5196198631 8959190466 9108592323 9757535430 6970329609 2612788905 8291385541 1909511821 2966775137 2142350335 0673549736 2433678594 3710004966 4441660007 2898267643 7578372627 8595508838 7113927333 1253595075 6853652176 7376544352 0696353785 4089656014 4119511519 9893074508 5823410303 9054405195 4400260190 9352758566 2928537189 0070728176 7069061762 2474584554 4592218603 1280393947 9559073767 6248330794 1984570746 0754829294 3696670344 5876949352 1689298919 9585030780 1687161779 4316000852 3704651153 6596788749 8541250802 2443713759 8570575830 6250020974 8062135735 7498849705 1734486742 2759405084 9426967733 9666752064 2494563084 6104239738 4423329011 8071895677 4317832887 6045691325 2589905287 9613744200 8929025019
2 4396771533 4500640132 5520164539 4648599497 7099947431 2400805357 6050983905 3001302568 3912193215 2748276310 2240552069 4340487588 3902816980 5062041005 6816990242 0169701624 0788829889 6729380404 3534872155 3136859688 0786096277 2378585625 7971736013 1974272139 4954429658 1003156323 4886443584 6800308612 0214053121

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) = 35.584117%

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 = 3 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 ≡ 61 (mod 64) and therefore cannot be a square and N is prime.