is 2 2637221 - 1
has 793883 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-LAFF0AFDCBB0E4940double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26711.267167.1642%2000000600000000.57797.6891%11.845069.6890%2.5248%
PrimeNet2590.029162.7119%110002000000.00242.7019%0.031563.7194%1.0075%
GPU722630.605265.0794%130002000000.00261.5733%0.607865.6288%0.5494%
Difference+4+10.6619+2.0848%+1987000+59800000+0.5753+6.1159%+11.2372+4.0602%+4.0602%

Known prime factors (1 factor, 72.2 bits, 0.00273615% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
263722152703092363966799508472272.158999216454820563
7 × 142745207831509
2018-05-027142745207831509554.42870,9821,626,751

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-31T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.295%
2009-06-21T08:28:00harleeP4_260030000420000---0.006--1.390%
2011-01-19T18:58:00James Heinrichi7-9201800004275000---0.045--3.598%
2016-12-26T22:14:23Jocelyn Larouchelow 4M171988171988---0.019--1.285%
2016-12-28T03:20:09Jocelyn Larouchelow 4M206385206385---0.023--1.408%
2017-04-27T04:20:48Jocelyn Larouchelow 4M36000036000006---0.060--3.796%
2019-07-04T12:47:03alpertronManual testing20000006000000012---0.578--7.689%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.029--
2016-02-23T16:29:18Mark RoseManual testing259260--0.029--
2009-01-31T07:24:00Sturle Sundefigaro.ifi260261--0.058--
2012-06-11T13:46:00Grant McCrackenthumper261262--0.116--
2013-01-14T11:57:00dbaughManual testing262263--0.372--
2015-02-23T17:25:00VictordeHollanderManual testing263264--0.744--
2015-02-23T17:25:00VictordeHollanderManual testing264265--1.417--
2016-01-19T09:40:26ramgeisManual testing265266--2.834--
2017-09-01T23:24:08Gordon SpenceManual testing266267--5.667--


ECM factoring results:

Old Calculation Method

Total ECM effort:3.818 GHz-days
Estimated T-Level:1.850
DigitsB1CurvesCompleteFacMiss
201100037 / 1000.37068.945%
255000037 / 2800.13287.601%

New Calculation Method

Total ECM effort:3.818 GHz-days
Estimated T-Level:1.850
DigitsB1CompleteFacMiss
20110001.19430.314%
25500000.10889.774%
302500000.00799.338%


ECM Summary

B1B2factorcurvesGHz-days
500005000000353.612
50000500000020.206


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-04T00:00:00ANONYMOUSv4_computersAFF0AFDCBB0E49400.204
1999-07-30T00:00:00ANONYMOUSv4_computersAFF0AFDCBB0E49400.204


PRP results:
dateuseridcompidcofactorsres64PRP
2018-05-03T14:08:48_p95holder_b_i3-4160T_v11
5270309236396679950847
7FFC2DD405FB38__no
2018-05-04T10:31:37NetaniasWin10
5270309236396679950847
7FFC2DD405FB38__no


P-1 factor-bounds graph:
B1 = 2000000, B2 = 60000000 (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: 2019-07-04T12:47:03+00:00