is 2 8626487 - 1
has 2596832 decimal digits
takes 2.252 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L17B9905BA8B9E852double-checked
PRP64BCC6C75C7CA22Averified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual272110.860266.6667%20500043562500.16322.5150%111.023467.5050%0.8383%
PrimeNet2640.412662.5000%3600010000000.03353.3045%0.446163.7392%1.2392%
GPU722686.909564.7059%5500012000000.04442.2938%6.954065.5155%0.8096%
Difference+4+103.9506+1.9608%+150000+3156250+0.1188+0.2212%+104.0694+1.9896%+1.9896%

Known prime factors (1 factor, 72.6 bits, 0.00084132% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
862648770421487492349580595772272.577408170136304324
22 × 29 × 3518708071589
2021-12-19293518708071589175.7672,583135,565

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-11-09T00:00:00ANONYMOUSv4_computers4000040000---0.015--0.309%
2012-06-04T10:40:00James Heinrich3930K2050004356250---0.163--2.515%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-12-19T05:21:58masserManual testing37500037500027P+12272.5770.216


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-11-07T00:00:00ANONYMOUSv4_computers21261--0.036--
1998-11-07T00:00:00ANONYMOUSv4_computers21262--0.071--
1999-03-26T00:00:00ANONYMOUSv4_computers21263--0.185--
1999-10-21T00:00:00ANONYMOUSv4_computers21264--0.413--
2012-06-03T18:52:00James HeinrichManual testing264265--0.433--
2015-05-25T09:34:00VictordeHollanderManual testing265266--0.866--
2016-02-03T20:13:19snme2pm1Manual testing266267--1.733--
2018-04-21T15:45:10monstManual testing267268--3.465--
2019-11-19T13:59:34mnd9Manual testing268269--6.930--
2021-08-22T16:36:53SRBaseManual testing269270--13.86--
2021-10-09T14:40:09Sid & AndyManual testing270271--27.72--
2021-10-17T07:26:56SRBaseManual testing271272--55.44--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.382 GHz-days
Estimated T-Level:0.300
DigitsB1CurvesCompleteFacMiss
20110006 / 1000.06094.148%
25500006 / 2800.02197.876%

New Calculation Method

Total ECM effort:2.382 GHz-days
Estimated T-Level:0.300
DigitsB1CompleteFacMiss
20110000.19482.403%
25500000.01798.266%
302500000.00199.892%


ECM Summary

B1B2factorcurvesGHz-days
50000500000062.382


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-12-08T00:00:00ANONYMOUSv4_computers17B9905BA8B9E8522.252
2003-01-09T00:00:00ANONYMOUSv4_computers17B9905BA8B9E8522.252


PRP results:
dateuseridcompidcofactorsres64PRP
2021-12-25T03:31:12kutensterra
7042148749234958059577
64BCC6C75C7CA22Ano


P-1 factor-bounds graph:
B1 = 205000, B2 = 4356250 (P-1 stage 2)
B1 = 375000 (P+1 stage 1)
B1 = 205000 (P-1 stage 1)
B1 = 40000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2021-12-25T03:31:12+00:00