is 2 2861741 - 1
has 861470 decimal digits
takes 0.221 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LE8164AF6999C9025double-checked
PRP3FCB1AE4D19F4DA2verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26820.828267.6471%2870000287000000.47906.4195%21.307269.7239%2.0769%
PrimeNet2590.026862.7119%130002400000.00282.9950%0.029763.8287%1.1168%
GPU722630.557765.0794%160002800000.00341.8685%0.561165.7319%0.6525%
Difference+5+20.2705+2.5677%+2854000+28420000+0.4756+4.5509%+20.7461+3.9921%+3.9921%

Known prime factors (1 factor, 76.8 bits, 0.00268483% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28617411345840378714687769161192476.83323514363786147799
4561 × 5155528126759
2020-10-21456151555281267599,745.331,45758,753

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.244%
2009-07-03T00:46:00Carsten Kossendeyleela15000157500---0.003--0.717%
2010-12-22T11:37:00Jocelyn LaroucheManual testing2000020000---0.002--0.272%
2011-01-03T14:35:00Jocelyn LaroucheManual testing3000030000---0.003--0.376%
2011-01-21T23:29:00Jocelyn LaroucheManual testing5000050000---0.006--0.544%
2011-02-08T20:49:00markrtiny1150002415000---0.027--2.654%
2016-08-24T03:41:15Jocelyn LaroucheManual testing15659948300006---0.046--3.272%
2016-12-19T18:37:52Jocelyn Larouchelow 4M187918187918---0.021--1.195%
2017-01-10T10:25:11Jocelyn Larouchelow 4M225501225501---0.025--1.312%
2017-04-01T09:06:05Jocelyn Larouchelow 4M32472132472106---0.054--3.333%
2018-08-27T00:20:23Jocelyn Larouchelow 4M85800817160166---0.101--3.027%
2018-08-30T21:10:22Jocelyn Larouchelow 4M85800825740246---0.107--3.417%
2019-10-23T17:34:48masserManual testing28700002870000012---0.479--6.419%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:23Mark RoseManual testing21260--0.054--
2009-02-14T09:14:00Sturle Sundeaalto.ifi260261--0.054--
2012-01-22T20:32:00lycornManual testing261262--0.107--
2013-01-10T10:24:00dbaughManual testing262263--0.343--
2015-04-21T09:21:00VictordeHollanderManual testing263264--0.686--
2015-04-21T09:21:00VictordeHollanderManual testing264265--1.306--
2016-02-18T12:13:55ramgeisManual testing265266--2.611--
2017-11-12T17:07:16Gordon SpenceManual testing266267--5.223--
2019-01-08T01:21:03chuenkitManual testing267268--10.45--


ECM factoring results:

Old Calculation Method

Total ECM effort:4.078 GHz-days
Estimated T-Level:1.950
DigitsB1CurvesCompleteFacMiss
201100039 / 1000.39067.573%
255000039 / 2800.13986.976%

New Calculation Method

Total ECM effort:4.078 GHz-days
Estimated T-Level:1.950
DigitsB1CompleteFacMiss
20110001.50022.313%
25500000.13987.041%
302500000.00999.128%


ECM Summary

B1B2factorcurvesGHz-days
500005000000383.973
50000500000010.105


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-01-13T00:00:00ANONYMOUSv4_computersE8164AF6999C90250.221
1999-05-23T00:00:00ANONYMOUSv4_computersE8164AF6999C90250.221


PRP results:
dateuseridcompidcofactorsres64PRP
2020-10-22T11:34:44mrhx
134584037871468776916119
3FCB1AE4D19F4DA2no


P-1 factor-bounds graph:
B1 = 2870000, B2 = 28700000 (P-1 stage 2)
B1 = 2870000 (P-1 stage 1)
B1 = 858008, B2 = 2574024 (P-1 stage 2)
B1 = 858008, B2 = 1716016 (P-1 stage 2)
B1 = 858008 (P-1 stage 1)
B1 = 324721, B2 = 3247210 (P-1 stage 2)
B1 = 156599, B2 = 4830000 (P-1 stage 2)
B1 = 324721 (P-1 stage 1)
B1 = 115000, B2 = 2415000 (P-1 stage 2)
B1 = 225501 (P-1 stage 1)
B1 = 187918 (P-1 stage 1)
B1 = 156599 (P-1 stage 1)
B1 = 115000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000, B2 = 157500 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
102
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104
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102
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1010
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1013
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
250
260
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290
2100
Last modified: 2020-10-22T11:34:44+00:00