is 2 2568187 - 1
has 773102 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-L-unknown--unknown-
PRP0DED313B595D6599verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26823.208967.6471%32000001120000000.91808.0785%24.126970.2607%2.6136%
PrimeNet2590.029962.7119%110002000000.00212.6888%0.032063.7145%1.0026%
GPU722630.621565.0794%120001800000.00211.4801%0.623665.5962%0.5169%
Difference+5+22.5875+2.5677%+3188000+111820000+0.9159+6.5984%+23.5034+4.6645%+4.6645%

Known prime factors (1 factor, 71.0 bits, 0.00276498% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
256818723773034491706384759512271.010462836905795925
52 × 59 × 79 × 3971996617
2021-01-03793971996617312.1221.76540.650

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-31T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.237%
2003-11-08T00:00:00Team Prime Ribv4_computers15000202500---0.003--0.761%
2010-12-21T01:09:00Jocelyn LaroucheManual testing2000020000---0.002--0.265%
2011-01-03T22:20:00Jocelyn LaroucheManual testing3000030000---0.003--0.367%
2011-01-10T23:57:00Jocelyn LaroucheManual testing5000050000---0.005--0.532%
2011-04-16T12:19:00James HeinrichWHS1750004112500---0.039--3.173%
2016-05-30T22:43:10mikrMSI320000011200000012---0.918--8.078%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.030--
2016-02-23T16:29:16Mark RoseManual testing259260--0.030--
2009-01-28T03:12:00Sturle Sundedittersdorf.ifi260261--0.060--
2012-06-17T16:43:00Sebastian HornbostelManual testing261262--0.120--
2013-01-14T11:55:00dbaughManual testing262263--0.382--
2015-02-23T17:24:00VictordeHollanderManual testing263264--0.764--
2015-02-23T17:24:00VictordeHollanderManual testing264265--1.455--
2015-11-08T21:03:03ramgeisManual testing265266--2.910--
2017-08-13T10:39:20Gordon SpenceManual testing266267--5.819--
2019-05-06T12:23:24TJAOIManual testing267268--11.64--


ECM factoring results:

Old Calculation Method

Total ECM effort:8.492 GHz-days
Estimated T-Level:4.600
DigitsB1CurvesCompleteFacMiss
201100092 / 1000.92039.668%
255000092 / 2800.32971.953%

New Calculation Method

Total ECM effort:8.492 GHz-days
Estimated T-Level:4.600
DigitsB1CompleteFacMiss
20110002.9685.142%
25500000.26876.474%
302500000.01798.362%


ECM Summary

B1B2factorcurvesGHz-days
500005000000857.846
50000500000070.646


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-23T00:00:00ANONYMOUSv4_computers07824040DD0E78__0.178


PRP results:
dateuseridcompidcofactorsres64PRP
2021-01-09T12:32:55Niels_Mache_Nextcloudconf4-a
2377303449170638475951
0DED313B595D6599no


P-1 factor-bounds graph:
B1 = 3200000, B2 = 112000000 (P-1 stage 2)
B1 = 3200000 (P-1 stage 1)
B1 = 175000, B2 = 4112500 (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 = 202500 (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)
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TF factor-bounds graph:
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265
264
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Last modified: 2021-01-09T12:32:55+00:00