is 2 42751 - 1
has 12870 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
-unknown- primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual267695.046176.1194%10000000020000000000.210711.0040%695.256878.7472%2.6278%
PrimeNet2400.000060.0000%500100000.00004.4877%0.000061.7951%1.7951%
GPU722440.000163.6364%500100000.00001.9499%0.000164.3454%0.7091%
Difference+23+695.0461+12.4830%+99999500+1999990000+0.2107+9.0541%+695.2568+14.4018%+14.4018%

Known prime factors (4 factors, 274.3 bits, 0.64152148% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
4275157474759902391342.38667220369
31 × 2168399
-3121683992.554e-50.00010.0002
4275179920651745211342.86293472260
22 × 3 × 5 × 7 × 222553
2008-08-2672225531.495e-51.256e-52.344e-5
4275176449596100566873902072272.69589412640757604353
7 × 643 × 414803 × 47890351
2009-04-224148034789035142,6760.00310.0050
4275110328251527127535322644942573568333736116.3141207954378508986377236198284668
22 × 32 × 17 × 1973781664230369897444768439
2021-10-251719737816642303698974447684393.428e+121.113e+172.079e+17

11 Composite Factors:
exponentprime factorscomposite factordigitsbits*
42751459342027029847108275005192685.248
427514393922180514771866095404191618947335115.081
427516109901546015369541391784748131584735115.557
4275135116512438447483079624267343527116978704801743348157.943
4275159361377673314795049762191678624947840140694754348158.700
4275182544059343649310354198945012543427753809665657748159.176
4275178959065767396308484943226586388314214484831936830
6880759
57189.009
4275147441999921448760042394901731757714770531856363071
88187151903
61201.562
4275145381533470981242455025218904629792791847408887338
14512443170820911401
70231.395
4275163104599973232129496348894128892036952566170337933
41075449462471941439
70231.871
4275136269217321978830637043854061848633338387202973518
577924103172532921890869343613921
83274.257
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-09-19T05:18:20kkmrkkblmbrbkManual testing100000000200000000012-
skipped known factor: 5747475990239
skipped known factor: 7992065174521
skipped known factor: 7644959610056687390207
--0.211--11.004%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2008-08-26T20:01:00ANONYMOUSManual testing??42.862131.24590e-66.20923e-52.53481e-6


ECM factoring results:

Old Calculation Method

Total ECM effort:23.906 GHz-days
Estimated T-Level:34.492
DigitsB1CurvesCompleteFacMiss
20110002272 / 10022.7200.000%
25500002272 / 2808.1140.029%
302500001990 / 6403.1094.452%
3510000001407 / 15660.89840.708%

New Calculation Method

Total ECM effort:23.906 GHz-days
Estimated T-Level:34.492
DigitsB1CompleteFacMiss
2011000298.3460.000%
255000056.5360.000%
302500008.3470.024%
3510000000.99936.826%
4030000000.09990.555%
45110000000.00899.173%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
5000050000002820.210
250000250000005832.171
100000010000000091613.64
10000001000000001251.862
10000001320000003666.019


Lucas-Lehmer results:
No L-L results for M42751


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-21T19:53:47Oliver KruseOllaptop415ACBDF70833B__?
2017-09-21T21:39:03Oliver KruseManual testing415ACBDF70833B__?
2017-10-02T10:53:54kkmrkkblmbrbkManual testing
5747475990239
7992065174521
7644959610056687390207
415ACBDF70833B__no
2017-12-07T03:16:58ATHxps
5747475990239
7992065174521
7644959610056687390207
415ACBDF70833B__no
2020-04-17T13:49:28Oliver KruseManual testing
5747475990239
7992065174521
7644959610056687390207
429077E3FC3621__no
2021-10-25T09:22:06mikrNitron
5747475990239
7992065174521
7644959610056687390207
103282515271275353226449425735683337
429077E3FC3621EFno


P-1 factor-bounds graph:
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
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1016
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TF factor-bounds graph:
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2120
Last modified: 2022-06-02T20:23:52+00:00