is 2 2560457 - 1
has 770775 decimal digits
takes 0.178 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L51C988011F6BB3A5double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26823.279067.6471%32000001120000000.91808.0761%24.197070.2599%2.6129%
PrimeNet2590.030062.7119%110002000000.00212.6873%0.032163.7139%1.0020%
GPU722630.623365.0794%120001800000.00211.4792%0.625565.5959%0.5166%
Difference+5+22.6557+2.5677%+3188000+111820000+0.9159+6.5969%+23.5715+4.6640%+4.6640%

Known prime factors (1 factor, 77.2 bits, 0.00301390% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
25604571699614419794417231167292477.17033189669262057852
22 × 13118213 × 632511251
2020-07-121311821363251125118,1434.71336.4733

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-23T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.237%
2003-11-08T00:00:00Team Prime Ribv4_computers15000198750---0.003--0.756%
2010-12-21T01:09:00Jocelyn LaroucheManual testing2000020000---0.002--0.265%
2011-01-03T14:36:00Jocelyn LaroucheManual testing3000030000---0.003--0.367%
2011-01-10T23:57:00Jocelyn LaroucheManual testing5000050000---0.005--0.531%
2011-04-11T23:39:00James HeinrichWHS1750004068750---0.039--3.164%
2016-04-24T18:03:50mikrMSI320000011200000012---0.918--8.076%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.030--
2016-02-23T16:29:16Mark RoseManual testing259260--0.030--
2009-02-01T14:15:00Sturle Sundehoffman.ifi260261--0.060--
2012-06-16T19:43:00Sebastian HornbostelManual testing261262--0.120--
2013-01-23T08:30:00dbaughManual testing262263--0.383--
2015-02-23T17:24:00VictordeHollanderManual testing263264--0.767--
2015-02-23T17:24:00VictordeHollanderManual testing264265--1.459--
2015-11-08T21:03:00ramgeisManual testing265266--2.919--
2017-08-11T09:15:23Gordon SpenceManual testing266267--5.837--
2019-07-01T11:10:59TJAOIManual testing267268--11.67--


ECM factoring results:

Old Calculation Method

Total ECM effort:4.060 GHz-days
Estimated T-Level:2.200
DigitsB1CurvesCompleteFacMiss
201100044 / 1000.44064.261%
255000044 / 2800.15785.434%

New Calculation Method

Total ECM effort:4.060 GHz-days
Estimated T-Level:2.200
DigitsB1CompleteFacMiss
20110001.41924.187%
25500000.12887.961%
302500000.00899.213%


ECM Summary

B1B2factorcurvesGHz-days
500005000000423.875
50000500000020.185


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-08-31T00:00:00ANONYMOUSv4_computers51C988011F6BB3A50.178
1999-09-22T00:00:00ANONYMOUSv4_computers51C988011F6BB3A50.178
2018-06-13T20:08:52kkmrkkblmbrbkold51C988011F6BB3A50.178


PRP results:
dateuseridcompidcofactorsres64PRP
2020-07-15T21:45:14nordisweet16
169961441979441723116729
BF57391000A6C702no
2020-07-15T23:34:11oodairacom2
169961441979441723116729
BF57391000A6C702no


P-1 factor-bounds graph:
B1 = 3200000, B2 = 112000000 (P-1 stage 2)
B1 = 3200000 (P-1 stage 1)
B1 = 175000, B2 = 4068750 (P-1 stage 2)
B1 = 175000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000, B2 = 198750 (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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108
102
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109
TF factor-bounds graph:
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Last modified: 2020-07-15T23:34:11+00:00