is 2 2597867 - 1
has 782036 decimal digits
takes 0.180 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LFBD9B8B62039FC03double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26822.943867.6471%32000001120000000.91808.0876%23.861870.2636%2.6166%
PrimeNet2590.029662.7119%110002000000.00212.6945%0.031763.7166%1.0047%
GPU722630.614465.0794%120002000000.00221.5301%0.616665.6137%0.5343%
Difference+5+22.3294+2.5677%+3188000+111800000+0.9158+6.5575%+23.2452+4.6500%+4.6500%

Known prime factors (1 factor, 69.2 bits, 0.00266465% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
25978676895108871142409036392169.224132707118400257
3 × 44235706133419
2020-07-1534423570613341956.087242,391452,718

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-31T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.238%
2003-11-08T00:00:00Team Prime Ribv4_computers15000217500---0.003--0.781%
2010-11-16T23:08:00Jocelyn LaroucheManual testing2000020000---0.002--0.266%
2011-01-15T02:57:00Jocelyn LaroucheManual testing5000050000---0.005--0.533%
2011-04-18T19:33:00James HeinrichWHS1750004156250---0.039--3.185%
2016-08-29T16:52:53mikrMSI320000011200000012---0.918--8.088%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.030--
2016-02-23T16:29:17Mark RoseManual testing259260--0.030--
2009-01-30T01:17:00Sturle Sundenouchcraft.ifi260261--0.059--
2012-06-23T11:43:00Sebastian HornbostelManual testing261262--0.118--
2013-09-08T16:47:00AxelssonManual testing262263--0.378--
2015-02-27T20:35:00VictordeHollanderManual testing263264--0.756--
2015-02-27T20:35:00VictordeHollanderManual testing264265--1.438--
2015-11-08T21:03:03ramgeisManual testing265266--2.876--
2017-08-21T17:34:51Gordon SpenceManual testing266267--5.753--
2019-03-18T11:45:38TJAOIManual testing267268--11.51--


ECM factoring results:

Old Calculation Method

Total ECM effort:3.884 GHz-days
Estimated T-Level:2.100
DigitsB1CurvesCompleteFacMiss
201100042 / 1000.42065.566%
255000042 / 2800.15086.048%

New Calculation Method

Total ECM effort:3.884 GHz-days
Estimated T-Level:2.100
DigitsB1CompleteFacMiss
20110001.61519.881%
25500000.14986.117%
302500000.00999.062%


ECM Summary

B1B2factorcurvesGHz-days
500005000000393.606
50000500000030.277


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-26T00:00:00ANONYMOUSv4_computersFBD9B8B62039FC030.180
2018-06-25T07:23:51kkmrkkblmbrbkoldFBD9B8B62039FC030.180


PRP results:
dateuseridcompidcofactorsres64PRP
2020-07-15T14:55:48mrh.orgw
689510887114240903639
2792AE0E08915EC8no
2020-07-15T16:31:26oodairacom2
689510887114240903639
2792AE0E08915EC8no


P-1 factor-bounds graph:
B1 = 3200000, B2 = 112000000 (P-1 stage 2)
B1 = 3200000 (P-1 stage 1)
B1 = 175000, B2 = 4156250 (P-1 stage 2)
B1 = 175000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 15000, B2 = 217500 (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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Last modified: 2020-07-15T16:31:26+00:00