Primality Certificate for (8684^2791-1)/8683

Andy Steward10,990 digits18 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 34.043069% factorization of N-1:

From Factorisation
86842 · 2 · 13 · 167
Φ23 · 3 · 5 · 193
Φ37 · 37 · 291199
Φ511 · 31 · 1096481 · 15211561
Φ63 · 25134391
Φ94159 · 662833 · 155569998000943
Φ105 · 1061 · 6151 · 174260171
Φ1561 · 171807321435601 · 3085581361314601
Φ183 · 142954435189211647384171
Φ30p32
Φ319262446043 · c109
Φ45181 · 82891 · 1735831 · 3563359468111 · 1307223458048973151 · 122797610136441244981 · p31
Φ62311 · 1117 · 14323 · c109
Φ90811 · c92
Φ93c237
Φ15531 · 4021209092851 · c459
Φ186113089 · 1235812087 · 1817837926911179791 · c204
Φ2798929 · 42650925859 · c695
Φ31047741 · p468
Φ4654651 · 165541 · 74067991 · 610940251 · 250408276231 · c909
Φ5583431143 · 78398228287 · c692
Φ9307725003736565881 · c930
Φ13952791 · 83701 · 17435415871 · c2818
Φ27903007621 · 1234517177703537578881 · p2809

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 :

203491558 2737866006 6435001003 0665804148 0936251328 2370152305 1927874316 4860689683 9402889769 3721033909 2579434630 1576699680 6473413157 0825907728 1763908699 9697060311 5225421926 2388804534 0314886457 4751921979 2892957225 6903860971 1690803349 6553754769 5979506191 3760354689 4212296056 4579309396 2469678561 7840209289 8147721600 0214989116 4150955864 2707183708 2222738431 8718612300 1536081305 3985967662 9186682663 7358784405 6758606791 2784324463 0652732997 9421947560 5542737830 5011591130 2852664369 4887841203 6297998195 4810167904 8941121694 2416596085 2477532307 5566039870 1948031886 7050479442 1428301001 4107076645 6367185189 8379910708 4273251509 2160951944 8371920607 2309864072 2734785200 3794075887 3038697380 0171219400 3560515024 9243597546 0938046218 4519200872 4717735135 1670640945 2138745774 7792874024 9324545424 1213498574 5413301213 3964858509 7329144566 8411073971 9774192806 5859434970 1904769216 9377993149 6438398821 1303722867 5050542481 2642578848 2984455614 6376323147 1706521291 8328405245 7451951486 1543649000 8066460383 6873623516 8780005795 8439325745 4678344947 2176646959 6503349887 7667075010 8619515617 4223887938 6606772928 5932816761 7128863317 6055307945 5546704472 0791084023 8618882373 3764738038 3132484395 0264248223 9965008052 4419151425 1724379726 1275897503 1147970491 1757650671 4100289395 1695605741 8310016208 7471190943 9564549445 3399522498 3783887495 8038039781 2217825422 6400998725 5845374712 3579846410 2308319749 0267710829 7952801999 4660996142 5598989159 3771066225 4862053710 4278811983 7428712755 8840951439 6413936634 5154264153 2817518217 4767572024 9853620177 5982319674 9936272852 4445613791 3814243721 6877208060 3610466566 1133316755 9909674408 2845063893 6333722174 2776699422 8978159284 3348914676 5664626875 9230314430 2233475656 2987252335 1732893399 0892547171 9298689456 1479301368 7288235033 7618262616 2891762213 2427583857 3764842176 6727390097 8102192454 6058814264 9201412535 2458826426 5546223579 8158377224 0899475373 8104381809 8737293011 4709701467 0502784017 8737357765 2636820660 0026712682 0185105047 5152017866 0165035479 5616822825 0357180351 8032449405 9271362923 0453336906 4638451837 7256880775 5621331312 5579849077 9817081048 0988654201 6222793571 6116793743 5232174077 4095490932 3276537132 6769142246 9575389841 0520369743 2924408755 3331634599 9011372547 6833887687 9588780159 7671522428 6610678749 0672564877 1884276519 8202788241 7273772494 6875253441 3896651157 1110170455 3265954015 0886198244 4781523789 9296742426 4837097720 3363964856 0346485316 4807519981 8899273766 6075631460 0324215602 2608137848 5038183087 5067047702 7240685648 3191036223 4605935580 8726073380 9425031436 1785116675 1463433216 7312575327 5070075004 7277334212 9215391574 3134047167 8910215869 9933501239 1847745945 8182714924 0645466606 4020776039 8164965495 3339606279 0474772755 6552521745 8749244932 0162058682 5280032031 8889254345 0791870491 3847390367 2201563707 3537215967 3419685475 1348735707 2555307816 5163602570 9341891394 4417291822 3448303433 5121155525 0819182847 4977896245 1854380301
92797498 6999947946 8027297424 8311615484 9688664386 2596628165 4115226319 5890818568 5412538721 5586854233 4840055570 4293156633 4428748560 8436351265 7692320715 2159575770 7405517968 1958912806 6795694037 1930876124 4567627873 3099400481 4377232637 3988536898 3517244319 9449589054 8033245446 8825489071 6769205011 7978731914 1883547404 1956972685 4565515179 3802167659 4970773175 6862892366 0808488351 9112174612 5691729171 1217897405 5568069270 5161314039 4914617627 8208255013 5181260723 0047213240 7115891761
32 3451020920 9603385935 6340847661
2 2708203507 4381266306 7178500141
1429 5443518921 1647384171
12 3451717770 3537578881
1 2279761013 6441244981
181783792 6911179791
130722345 8048973151
772500 3736565881
308558 1361314601
17180 7321435601
15556 9998000943
402 1209092851
356 3359468111
25 0408276231
7 8398228287
4 2650925859
1 7435415871
9262446043
1235812087
610940251
174260171
74067991
25134391
15211561
3431143
3007621
1735831
1096481
662833
291199
165541

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) = 33.372507%

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 ≡ 53 (mod 64) and therefore cannot be a square and N is prime.