is 2 1508251 - 1
has 454029 decimal digits
takes 0.067 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L559049F1E9803D7Edouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26979.155869.5652%100000002000000001.31818.3595%80.473972.1094%2.5442%
PrimeNet2570.012763.1579%65001000000.00082.3429%0.013564.0211%0.8632%
GPU722610.203765.5738%6000500000.00050.9491%0.204265.9005%0.3267%
Difference+8+78.9521+3.9914%+9994000+199950000+1.3176+7.4104%+80.2697+6.2089%+6.2089%

Known prime factors:
No known factors for M1508251

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2011-01-26T12:36:00James HeinrichWHS800001280000---0.009--1.683%
2013-11-16T02:00:00David Campeaui5-2500k93500027115000---0.153--4.917%
2015-01-21T15:38:00VictordeHollanderManual testing10000000200000000---1.318--8.360%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2003-08-08T00:00:00ANONYMOUSv4_computers21258--0.025--
2016-02-23T16:28:36Mark RoseManual testing258261--0.178--
2016-02-23T16:28:36Mark RoseManual testing261262--0.204--
2010-04-04T04:46:00GrunwalderGIMPManual testing21263--1.058--
2016-02-23T16:28:36Mark RoseManual testing262263--0.651--
2015-01-13T21:57:00snme2pm1Manual testing263264--1.302--
2015-01-13T21:57:00snme2pm1Manual testing264265--2.477--
2015-09-27T20:41:25ramgeisManual testing265266--4.955--
2018-03-19T15:07:59TJAOIManual testing266267--9.91--
2018-06-06T17:06:40ramgeisManual testing267268--19.82--
2019-11-04T13:15:47mnd9Manual testing268269--39.64--


ECM factoring results:

Old Calculation Method

Total ECM effort:29.626 GHz-days
Estimated T-Level:25.336
DigitsB1CurvesCompleteFacMiss
2011000325 / 1003.2503.815%
2550000325 / 2801.16131.261%
3025000043 / 6400.06793.497%

New Calculation Method

Total ECM effort:29.626 GHz-days
Estimated T-Level:25.336
DigitsB1CompleteFacMiss
201100015.1670.000%
25500001.65819.049%
302500000.13687.264%
3510000000.00999.087%


ECM Summary

B1B2factorcurvesGHz-days
50000500000028015.61
735001140000010.099
75000750000010.084
250000350000004313.83


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-02T00:00:00ANONYMOUSv4_computers559049F1E9803D7E0.067
2015-07-21T00:18:00MadPooManual testing559049F1E9803D7E0.067


PRP results:
No PRP results for M1508251


P-1 factor-bounds graph:
B1 = 10000000, B2 = 200000000 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
B1 = 935000, B2 = 27115000 (P-1 stage 2)
B1 = 935000 (P-1 stage 1)
B1 = 80000, B2 = 1280000 (P-1 stage 2)
B1 = 80000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-02-03T11:47:11+00:00