is 2 2651581 - 1
has 798206 decimal digits
takes 0.205 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L90731920C708C85Edouble-checked
PRPE79007B20F69D353PRP-tested

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26945.024868.1159%2000000500000000.51696.2932%45.541670.1225%2.0065%
PrimeNet2590.029062.7119%110002000000.00242.7046%0.031363.7204%1.0085%
GPU722630.601965.0794%130002000000.00261.5749%0.604565.6293%0.5500%
Difference+6+44.4228+3.0366%+1987000+49800000+0.5143+4.7182%+44.9371+4.4931%+1.4565%

Known prime factors (1 factor, 75.8 bits, 0.00285917% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2651581663804621557948075234092375.81312517147723526984
23 × 29 × 2830049 × 19064413
2021-07-152830049190644135,049.60.41600.6450

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-31T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.193%
2009-06-23T01:33:00harleeP4_260030000420000---0.006--1.045%
2011-01-19T08:54:00James Heinrichi7-9201800004275000---0.045--2.891%
2016-12-29T21:56:31Jocelyn Larouchelow 4M171988171988---0.019--0.985%
2017-01-10T10:24:56Jocelyn Larouchelow 4M206385206385---0.023--1.086%
2017-05-08T05:55:51Jocelyn Larouchelow 4M36000036000006---0.060--3.081%
2019-11-24T14:34:21masserManual testing20000005000000012---0.517--6.293%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-04-02T00:00:00ANONYMOUSv4_computers21259--0.029--
2016-02-23T16:29:18Mark RoseManual testing259260--0.029--
2009-01-27T23:41:00Sturle Sundegehry.ifi260261--0.058--
2012-05-29T03:01:00markroldgamer261262--0.116--
2013-01-14T11:57:00dbaughManual testing262263--0.370--
2015-02-23T17:25:00VictordeHollanderManual testing263264--0.740--
2015-02-23T17:25:00VictordeHollanderManual testing264265--1.409--
2016-01-21T23:03:51ramgeisManual testing265266--2.818--
2017-09-08T08:21:17Gordon SpenceManual testing266267--5.636--
2019-05-20T13:24:23TJAOIManual testing267268--11.27--
2021-06-07T10:36:38TJAOIManual testing268269--22.55--


ECM factoring results:
Total ECM effort:11.940 GHz-days
Estimated T-Level:22.052
DigitsB1CompleteFacMiss
20110004.4361.184%
25500000.41066.338%
302500000.02697.444%
3510000000.00199.879%


ECM Summary

B1B2factorcurvesGHz-days
50000500000011111.46
50000675000040.475


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-02T00:00:00ANONYMOUSv4_computers90731920C708C85E0.205
2018-07-19T13:41:03kkmrkkblmbrbkold90731920C708C85E0.205


PRP results:
dateuseridcompidcofactorsres64PRP
2021-07-16T01:09:39GURA LOVE
66380462155794807523409
E79007B20F69D353no


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: 2021-07-16T01:09:39+00:00