is 2 2512943 - 1
has 756472 decimal digits
takes 0.174 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L2D9C0E93F89002C3double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26823.719267.6471%32000001120000000.91808.0613%24.637270.2551%2.6081%
PrimeNet2590.030662.7119%110001900000.00212.6415%0.032663.6968%0.9850%
GPU722630.635165.0794%110001700000.00201.4089%0.637165.5714%0.4920%
Difference+5+23.0840+2.5677%+3189000+111830000+0.9160+6.6523%+24.0001+4.6837%+4.6837%

Known prime factors (1 factor, 72.5 bits, 0.00288493% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
251294366626427397370345975512272.4971325665313486425
52 × 17 × 3119212502321
2020-07-07253119212502321639.6717,09231,923

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-23T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.235%
2003-10-31T00:00:00Team Prime Ribv4_computers15000236250---0.003--0.795%
2010-12-19T21:41:00Jocelyn LaroucheManual testing2000020000---0.002--0.264%
2011-01-01T13:18:00Jocelyn LaroucheManual testing3000030000---0.003--0.366%
2011-01-06T01:05:00Jocelyn LaroucheManual testing5000050000---0.005--0.529%
2011-10-05T13:10:00markrtiny1700003952500---0.038--3.120%
2016-03-07T15:59:50mikrMSI320000011200000012---0.918--8.061%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-15T00:00:00ANONYMOUSv4_computers21259--0.031--
2016-02-23T16:29:15Mark RoseManual testing259260--0.031--
2009-01-30T18:36:00Sturle Sundeherrick.ifi260261--0.061--
2012-06-13T00:43:00Sebastian HornbostelManual testing261262--0.122--
2013-12-04T21:12:00Jerry HallettManual testing262263--0.391--
2015-02-18T11:36:00VictordeHollanderManual testing263264--0.781--
2015-02-18T11:36:00VictordeHollanderManual testing264265--1.487--
2015-11-05T09:47:22ramgeisManual testing265266--2.974--
2017-07-31T07:56:50Gordon SpenceManual testing266267--5.947--
2019-05-06T12:23:26TJAOIManual testing267268--11.89--


ECM factoring results:

Old Calculation Method

Total ECM effort:4.416 GHz-days
Estimated T-Level:2.400
DigitsB1CurvesCompleteFacMiss
201100048 / 1000.48061.729%
255000048 / 2800.17184.220%

New Calculation Method

Total ECM effort:4.416 GHz-days
Estimated T-Level:2.400
DigitsB1CompleteFacMiss
20110001.54821.259%
25500000.14086.941%
302500000.00999.142%


ECM Summary

B1B2factorcurvesGHz-days
500005000000454.140
50000500000030.276


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-13T00:00:00ANONYMOUSv4_computers2D9C0E93F89002C30.174
2018-06-04T14:30:04kkmrkkblmbrbkold2D9C0E93F89002C30.174


PRP results:
dateuseridcompidcofactorsres64PRP
2020-07-07T08:28:38CrypticClueManual testing
6662642739737034597551
A3CF2703653F4883no
2020-07-07T08:49:48ATHec2-PRPCFDC
6662642739737034597551
A3CF2703653F4883no


P-1 factor-bounds graph:
B1 = 3200000, B2 = 112000000 (P-1 stage 2)
B1 = 3200000 (P-1 stage 1)
B1 = 170000, B2 = 3952500 (P-1 stage 2)
B1 = 170000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000, B2 = 236250 (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: 2020-07-07T08:49:48+00:00