is 2 2580521 - 1
has 776815 decimal digits
takes 0.179 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L5F0B9EE4CABC3346double-checked
PRP9A38ABBEB1F9B240verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26823.098067.6471%32000001120000000.91808.0823%24.016070.2619%2.6149%
PrimeNet2590.029862.7119%110002000000.00212.6912%0.031963.7153%1.0035%
GPU722630.618565.0794%120001900000.00221.5053%0.620765.6050%0.5257%
Difference+5+22.4795+2.5677%+3188000+111810000+0.9158+6.5769%+23.3953+4.6569%+4.6569%

Known prime factors (1 factor, 80.9 bits, 0.00313327% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
258052121863253266432427955971612580.855423620913498328980
22 × 32 × 5 × 73 × 12553 × 546591959
2021-03-1512553546591959163,9022.99635.5939

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-31T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.237%
2003-11-08T00:00:00Team Prime Ribv4_computers15000206250---0.003--0.766%
2010-12-21T22:27:00Jocelyn LaroucheManual testing2000020000---0.002--0.266%
2011-01-12T23:59:00Jocelyn LaroucheManual testing5000050000---0.005--0.532%
2011-10-10T05:19:00markrtiny1750004112500---0.039--3.175%
2016-07-18T23:48:43mikrMSI320000011200000012---0.918--8.082%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.030--
2016-02-23T16:29:17Mark RoseManual testing259260--0.030--
2009-01-30T19:26:00Sturle Sundekinner.ifi260261--0.060--
2012-06-20T17:42:00Sebastian HornbostelManual testing261262--0.119--
2013-09-08T16:47:00AxelssonManual testing262263--0.380--
2015-02-27T20:35:00VictordeHollanderManual testing263264--0.761--
2015-02-27T20:35:00VictordeHollanderManual testing264265--1.448--
2015-11-08T21:03:07ramgeisManual testing265266--2.896--
2017-08-20T12:59:34Gordon SpenceManual testing266267--5.792--
2019-06-28T18:42:22lycornManual testing267268--11.58--


ECM factoring results:

Old Calculation Method

Total ECM effort:9.699 GHz-days
Estimated T-Level:21.875
DigitsB1CurvesCompleteFacMiss
2011000105 / 1001.05034.809%
2550000105 / 2800.37568.683%

New Calculation Method

Total ECM effort:9.699 GHz-days
Estimated T-Level:21.875
DigitsB1CompleteFacMiss
20110003.3873.381%
25500000.30673.630%
302500000.01998.133%


ECM Summary

B1B2factorcurvesGHz-days
500005000000999.145
50000500000060.554


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-13T00:00:00ANONYMOUSv4_computers5F0B9EE4CABC33460.179
2018-06-19T02:51:58kkmrkkblmbrbkold5F0B9EE4CABC33460.179


PRP results:
dateuseridcompidcofactorsres64PRP
2021-03-16T12:00:38daveward2005Davy
2186325326643242795597161
9A38ABBEB1F9B240no


P-1 factor-bounds graph:
B1 = 3200000, B2 = 112000000 (P-1 stage 2)
B1 = 3200000 (P-1 stage 1)
B1 = 175000, B2 = 4112500 (P-1 stage 2)
B1 = 175000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 15000, B2 = 206250 (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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266
265
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Last modified: 2021-03-16T12:00:38+00:00