is 2 2647079 - 1
has 796851 decimal digits
takes 0.204 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LF3FBD031EAC6D58Edouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26822.517267.6471%2000000500000000.51696.8571%23.034169.8655%2.2185%
PrimeNet2590.029062.7119%110002000000.00242.7038%0.031463.7201%1.0082%
GPU722630.602965.0794%130002000000.00261.5744%0.605565.6292%0.5498%
Difference+5+21.9143+2.5677%+1987000+49800000+0.5143+5.2827%+22.4286+4.2364%+4.2364%

Known prime factors (1 factor, 72.6 bits, 0.00274128% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
264707969801651366838448205772272.5641318465587291472
24 × 82404099205717
2020-08-031682404099205717506.13502,801939,093

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-31T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.239%
2009-06-22T10:42:00harleeP4_260030000420000---0.006--1.207%
2011-01-20T09:28:00James Heinrichi7-9201800004275000---0.045--3.228%
2016-12-28T03:20:12Jocelyn Larouchelow 4M171988171988---0.019--1.126%
2016-12-29T21:56:29Jocelyn Larouchelow 4M206385206385---0.023--1.238%
2017-05-08T05:55:49Jocelyn Larouchelow 4M36000036000006---0.060--3.422%
2019-11-28T16:16:15masserManual testing20000005000000012---0.517--6.857%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.029--
2016-02-23T16:29:18Mark RoseManual testing259260--0.029--
2009-01-30T04:33:00Sturle Sundegolan.ifi260261--0.058--
2012-06-11T15:03:00markroldgamer261262--0.116--
2013-01-14T11:57:00dbaughManual testing262263--0.371--
2015-02-23T17:25:00VictordeHollanderManual testing263264--0.742--
2015-02-23T17:25:00VictordeHollanderManual testing264265--1.412--
2016-01-21T23:03:49ramgeisManual testing265266--2.823--
2017-09-08T08:21:16Gordon SpenceManual testing266267--5.646--
2019-02-25T14:14:28TJAOIManual testing267268--11.29--


ECM factoring results:

Old Calculation Method

Total ECM effort:4.543 GHz-days
Estimated T-Level:2.200
DigitsB1CurvesCompleteFacMiss
201100044 / 1000.44064.261%
255000044 / 2800.15785.434%

New Calculation Method

Total ECM effort:4.543 GHz-days
Estimated T-Level:2.200
DigitsB1CompleteFacMiss
20110001.41924.187%
25500000.12887.961%
302500000.00899.213%


ECM Summary

B1B2factorcurvesGHz-days
500005000000424.337
50000500000020.207


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-23T00:00:00ANONYMOUSv4_computersF3FBD031EAC6D58E0.204
2018-07-16T08:37:48kkmrkkblmbrbkoldF3FBD031EAC6D58E0.204


PRP results:
dateuseridcompidcofactorsres64PRP
2020-08-03T10:45:22CrypticCluecruncher
6980165136683844820577
20C28197E9A2FC90no
2020-08-04T09:20:18marssystemssystem11
6980165136683844820577
20C28197E9A2FC90no


P-1 factor-bounds graph:
B1 = 2000000, B2 = 50000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 360000, B2 = 3600000 (P-1 stage 2)
B1 = 180000, B2 = 4275000 (P-1 stage 2)
B1 = 360000 (P-1 stage 1)
B1 = 206385 (P-1 stage 1)
B1 = 180000 (P-1 stage 1)
B1 = 171988 (P-1 stage 1)
B1 = 30000, B2 = 420000 (P-1 stage 2)
B1 = 30000 (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: 2020-08-04T09:20:18+00:00