is 2 8185757 - 1
has 2464159 decimal digits
takes 2.137 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LCA0B3D7178B40CC8double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual2687.281566.1765%21500054287500.18894.0669%7.470567.5520%1.3756%
PrimeNet2630.195063.4921%360009000000.03153.6188%0.226464.8132%1.3212%
GPU722673.630065.6716%5500013000000.04652.6257%3.676566.5730%0.9014%
Difference+1+3.6516+0.5048%+160000+4128750+0.1424+1.4411%+3.7940+0.9790%+0.9790%

Known prime factors (1 factor, 88.2 bits, 0.00107768% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
81857573594728410893851137960233592788.21621957214286313722347
11621 × 1889442757621007
2019-10-301162118894427576210078,564,60638,975,00572,794,456

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-08-10T00:00:00ANONYMOUSv4_computers40000280000---0.020--1.410%
2003-02-09T00:00:00ANONYMOUSv4_computers40000410000---0.023--1.586%
2012-09-30T17:11:00James Heinrichi7-9202150005428750---0.189--4.067%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-09-06T00:00:00mhoneyv4_computers21263--0.195--
2013-08-23T13:17:00David CampeauManual testing263264--0.240--
2014-01-02T21:19:00David CampeauManual testing264265--0.456--
2015-05-28T21:45:00snme2pm1Manual testing265266--0.913--
2015-12-07T20:29:08snme2pm1Manual testing266267--1.826--
2018-07-09T05:28:01chuenkitManual testing267268--3.652--


ECM factoring results:

Old Calculation Method

Total ECM effort:1.588 GHz-days
Estimated T-Level:0.200
DigitsB1CurvesCompleteFacMiss
20110004 / 1000.04096.060%
25500004 / 2800.01498.579%

New Calculation Method

Total ECM effort:1.588 GHz-days
Estimated T-Level:0.200
DigitsB1CompleteFacMiss
20110000.15485.740%
25500000.01498.587%


ECM Summary

B1B2factorcurvesGHz-days
50000500000031.191
50000500000010.397


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2000-02-09T00:00:00ANONYMOUSv4_computersCA0B3D7178B40CC82.137
2003-03-27T00:00:00ANONYMOUSv4_computersCA0B3D7178B40CC82.137


PRP results:
dateuseridcompidcofactorsres64PRP
2019-11-01T01:14:13treborLaptop
359472841089385113796023359
8D2B224AA1F9ABFBno
2020-03-01T04:36:54oodairacom1
359472841089385113796023359
8D2B224AA1F9ABFBno


P-1 factor-bounds graph:
B1 = 215000, B2 = 5428750 (P-1 stage 2)
B1 = 215000 (P-1 stage 1)
B1 = 40000, B2 = 410000 (P-1 stage 2)
B1 = 40000, B2 = 280000 (P-1 stage 2)
B1 = 40000 (P-1 stage 1)
103
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105
106
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104
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109
1010
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1016
TF factor-bounds graph:
268
267
266
265
264
263
250
260
270
280
290
2100
Last modified: 2020-03-01T04:36:54+00:00