Primality Certificate for (3709^2161-1)/3708

Andy Steward7,710 digits24 January 2001
Originally by David Broadhurst 2001

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 33.390675% factorization of N-1:

From Factorisation
37093709
Φ22 · 5 · 7 · 53
Φ33 · 4586797
Φ42 · 6878341
Φ5189297309425981
Φ613 · 691 · 1531
Φ82 · 137 · 468641 · 1473793
Φ93 · 19 · 19 · 37 · 17209 · 3775332308689
Φ105 · 11 · 71 · 48449491001
Φ12189246258379081
Φ1531 · 151 · 241 · 31738169491723750785241
Φ162 · 17 · 769 · 10369 · 991409 · 4183937 · 31847441
Φ18163 · 487 · 32796268580136673
Φ201806221 · 12003689981 · 1651843799161
Φ242857 · 674569804561 · 18583072834393
Φ273 · 109 · 228961 · 9420571 · 384822631 · p41
Φ3061 · 34651 · 471391 · 97389931 · 369173731
Φ36181 · 8101 · 10331895961 · 6235844016313 · 71744650682977
Φ4041 · 5801 · 40812241 · 29387770206121 · p31
Φ451171 · 17840126453213930857545635101 · p55
Φ486079107849782812332673 · p36
Φ54757 · 44389 · 522883 · 684559 · 1550580732932311 · p30
Φ603238864501 · p48
Φ7273 · 15817454171769060099839922995834235542593 · p44
Φ8040754730839080494053913245201 · 28829170957572773020856048556961 · p55
Φ902575351 · 100887834474079382062385126478361 · p48
Φ108228284569 · 1095396456797879833 · 64596896898057470248633 · 13659853666406402190328576516873 · p49
Φ120c115
Φ135541 · 2971 · 1155601 · 39297655087708861 · 1313538946482488311 · c211
Φ14428513 · 145533039876001 · 6104774585501649608833 · p131
Φ18024558018163561 · 29448147037647866251992007787707782601 · c121
Φ2161297 · 309313 · 593353 · c243
Φ240941041 · 12785761 · c216
Φ270271 · c255
Φ3602161 · 13417575121 · 15575620142881 · 406678217617914120503281 · 4040065324083462933092436721 · c265
Φ432433 · 32356801 · c504
Φ540105725789461 · c503
Φ720242709121 · c677
Φ1080122041 · 5774761 · 430421799749761 · p1002
Φ2160211681 · 3892469041 · 215885861281 · c2030

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 :

29 1094478078 4136314326 7104299188 8821960427 4606798681 0114316380 3076798870 3096878260 9581744648 3381038361 2969415352 2033184672 7704020001 5440960740 2572287599 6086414677 2928125925 6392489572 0948486826 8425951351 9776926661 7210622060 4641409928 1292794205 3023499862 9064926046 6764116946 9795908129 6281175018 6299662443 0108033851 4961183110 4311735257 0018817280 3955353370 3221739717 6764751208 5811584714 7685216916 0429554070 0063841545 3371072117 2228253312 5098528099 0618896457 2915675779 2088318466 3231054985 5090475211 5556375827 0326165708 1611234792 2380070526 6780568773 9318657552 3294896753 1677093795 6777779709 6659413067 3705030935 6006770029 9365253670 5087003110 5111775010 6410056516 9748409376 6865946861 6519264262 2389357860 4531632582 6732093694 2179561506 6491039214 9951208816 4655029681 0333822705 9148031934 9261519957 1091131523 0142420806 9646920215 6798216987 6669465107 2967177439 1938121096 3472821637 4024557471 9220154911 3891091441 0955495535 2719269565 5291636106 6645888315 2570140355 9947130641 1625581859 8699855100 4378658602 1086481713 3153552801
8 3301697647 7171255612 6580060529 6428167332 2640926195 2213719992 6743491704 2034625689 3695455738 2652820471 3476013395 2949161536 8729875809
21989 1871927402 8464967289 0090342927 6811585849 7507100711
14002 5935799322 5915570088 1363923271 0528337482 2745844881
141104352 1353992515 3841067847 3492749327 7126246297
39601951 2932829710 3806487378 2575941321 9853716221
17680265 0531270586 4542051364 3537663356 8570901871
3978 3643534921 7374002862 8777705814 7331077929
6 5009361783 8475038070 8700499345 7971991413
1 5817454171 7690600998 3992299583 4235542593
29448147 0376478662 5199200778 7707782601
210993 6985159252 2128929701 0657074977
100 8878344740 7938206238 5126478361
28 8291709575 7277302085 6048556961
13 6598536664 0640219032 8576516873
4 4964061510 9846822697 0425682521
9461107324 4687512960 3010606863
407547308 3908049405 3913245201
178401264 5321393085 7545635101
40400653 2408346293 3092436721
4066 7821761791 4120503281
645 9689689805 7470248633
317 3816949172 3750785241
61 0477458550 1649608833
60 7910784978 2812332673
131353894 6482488311
109539645 6797879833
3929765 5087708861
3279626 8580136673
155058 0732932311
43042 1799749761
18929 7309425981
18924 6258379081
14553 3039876001
7174 4650682977
2938 7770206121
2455 8018163561
1858 3072834393
1557 5620142881
623 5844016313
377 5332308689
165 1843799161
67 4569804561
21 5885861281
10 5725789461
4 8449491001
1 3417575121
1 2003689981
1 0331895961
3892469041
3238864501
384822631
369173731
242709121
228284569
97389931
40812241
32356801
31847441
12785761
9420571
6878341
5774761
4586797
4183937
2575351
1806221
1473793
1155601
991409
941041
684559
593353
522883
471391
468641
309313
228961
211681
122041
44389
34651
28513
17209
10369
8101
5801
3709
2971
2857
2161
1531
1297
1171
769
757
691
541
487
433
271
241
181
163
151
137
109
73
71
61
53
41
37
31
192
17
13
11
7

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) = 33.338358%

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 = 59 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 ≡ 28 (mod 64) and therefore cannot be a square and N is prime.