is 2 2627789 - 1
has 791044 decimal digits
takes 0.203 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-
PRPC4C8D7FD12C8370Cverified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26822.682567.6471%80000002500000002.37259.6694%25.055170.7754%3.1283%
PrimeNet2590.029262.7119%110002000000.00242.7002%0.031663.7187%1.0068%
GPU722630.607465.0794%130002000000.00261.5722%0.610065.6284%0.5490%
Difference+5+22.0752+2.5677%+7987000+249800000+2.3699+8.0972%+24.4451+5.1470%+5.1470%

Known prime factors (1 factor, 79.7 bits, 0.00303376% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
26277899962320758167897130592012479.721189557090736126400
26 × 52 × 7 × 16924740244297
2021-03-10641692474024429787,536103,269192,878

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--0.782%
2010-12-21T22:27:00Jocelyn LaroucheManual testing2000020000---0.002--0.267%
2010-12-26T02:29:00Jocelyn LaroucheManual testing3000030000---0.003--0.369%
2011-01-20T22:46:00Jocelyn LaroucheManual testing5000050000---0.006--0.534%
2011-02-28T05:06:00James Heinrichi7-9203000008000000---0.081--3.975%
2018-07-27T08:56:21mikrS068800000025000000012---2.373--9.669%
2019-10-21T15:48:25masserManual testing26300002630000012---0.439--6.222%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.029--
2016-02-23T16:29:17Mark RoseManual testing259260--0.029--
2009-02-13T16:21:00Sturle Sundeghibu.ifi260261--0.058--
2012-06-16T11:34:00Grant McCrackenhome261262--0.117--
2013-01-14T11:57:00dbaughManual testing262263--0.374--
2015-02-23T17:25:00VictordeHollanderManual testing263264--0.747--
2015-02-23T17:25:00VictordeHollanderManual testing264265--1.422--
2016-01-18T09:58:45ramgeisManual testing265266--2.844--
2017-09-01T23:24:07Gordon SpenceManual testing266267--5.687--
2019-04-01T13:34:42TJAOIManual testing267268--11.37--


ECM factoring results:

Old Calculation Method

Total ECM effort:10.005 GHz-days
Estimated T-Level:4.850
DigitsB1CurvesCompleteFacMiss
201100097 / 1000.97037.724%
255000097 / 2800.34670.677%

New Calculation Method

Total ECM effort:10.005 GHz-days
Estimated T-Level:4.850
DigitsB1CompleteFacMiss
20110003.1294.376%
25500000.28375.367%
302500000.01798.274%


ECM Summary

B1B2factorcurvesGHz-days
500005000000939.59
50000500000040.413


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-02T00:00:00ANONYMOUSv4_computers17260CB5CE97B9__0.203
1999-08-22T00:00:00ANONYMOUSv4_computers2824CD9A974105__0.203


PRP results:
dateuseridcompidcofactorsres64PRP
2021-03-11T00:29:46riccardo ubertiTuareg8C
996232075816789713059201
C4C8D7FD12C8370Cno


P-1 factor-bounds graph:
B1 = 8000000, B2 = 250000000 (P-1 stage 2)
B1 = 8000000 (P-1 stage 1)
B1 = 2630000, B2 = 26300000 (P-1 stage 2)
B1 = 2630000 (P-1 stage 1)
B1 = 300000, B2 = 8000000 (P-1 stage 2)
B1 = 300000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (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: 2021-03-11T00:29:46+00:00