is 2 2248639 - 1
has 676908 decimal digits
takes 0.148 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LA78D2A25965C165Ddouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26826.507167.6471%1000000200000000.19405.3746%26.701169.3859%1.7388%
PrimeNet2580.017162.0690%100001800000.00182.8746%0.018963.1593%1.0904%
GPU722620.273264.5161%110001900000.00201.6597%0.275265.1051%0.5889%
Difference+6+26.2339+3.1309%+989000+19810000+0.1920+3.7148%+26.4259+4.2808%+4.2808%

Known prime factors (1 factor, 68.7 bits, 0.00305581% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
22486394841756997749142528172168.714107659722119672
23 × 23 × 585107185433
2020-04-122358510718543347.0623,039.25,676.4

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-04-03T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.228%
2010-11-06T12:26:00Jocelyn LaroucheManual testing1500015000---0.001--0.200%
2010-11-11T18:49:00Oscar Östlin7501175011---0.007--0.676%
2011-01-14T11:22:00Oscar Östlin850001636250---0.016--2.194%
2014-06-01T23:28:00Jocelyn LaroucheManual testing113544113544---0.011--0.869%
2014-10-03T21:04:00Jocelyn LaroucheManual testing142088142088---0.014--0.987%
2015-12-06T08:24:54Alexander DubrovinManual testing10000002000000012---0.194--5.375%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-07-30T00:00:00ANONYMOUSv4_computers21258--0.017--
2000-01-25T00:00:00ANONYMOUSv4_computers21258--0.017--
2016-02-23T16:29:10Mark RoseManual testing258260--0.051--
2009-01-10T21:42:00Sturle Sundewright.ifi260261--0.068--
2012-05-04T08:48:00Sebastian HornbostelManual testing261262--0.137--
2013-01-23T08:24:00dbaughManual testing262263--0.437--
2015-03-10T10:44:00VictordeHollanderManual testing263264--0.873--
2015-03-10T10:44:00VictordeHollanderManual testing264265--1.662--
2015-10-27T09:37:30ramgeisManual testing265266--3.323--
2017-01-13T17:42:43ConductorManual testing266267--6.646--
2019-03-25T14:11:05TJAOIManual testing267268--13.29--


ECM factoring results:

Old Calculation Method

Total ECM effort:5.152 GHz-days
Estimated T-Level:3.000
DigitsB1CurvesCompleteFacMiss
201100060 / 1000.60054.716%
255000060 / 2800.21480.681%

New Calculation Method

Total ECM effort:5.152 GHz-days
Estimated T-Level:3.000
DigitsB1CompleteFacMiss
20110001.93514.435%
25500000.17583.952%
302500000.01198.929%


ECM Summary

B1B2factorcurvesGHz-days
500005000000574.894
50000500000030.258


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-26T00:00:00ANONYMOUSv4_computersA78D2A25965C165D0.148
2018-04-22T21:25:13kkmrkkblmbrbkoldA78D2A25965C165D0.148


PRP results:
dateuseridcompidcofactorsres64PRP
2020-04-13T03:00:58CrypticCluecruncher
484175699774914252817
6D80888F1D1FF8FEno
2020-04-15T14:59:47arnaudstm-11-010
484175699774914252817
6D80888F1D1FF8FEno


P-1 factor-bounds graph:
B1 = 1000000, B2 = 20000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 85000, B2 = 1636250 (P-1 stage 2)
B1 = 142088 (P-1 stage 1)
B1 = 113544 (P-1 stage 1)
B1 = 85000 (P-1 stage 1)
B1 = 75011 (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: 2020-04-15T14:59:47+00:00