is 2 2876813 - 1
has 866008 decimal digits
takes 0.222 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L893138841F5F735Bdouble-checked
PRP6C3562485A50F350verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26941.499768.1159%50000002000000001.74988.5025%43.249570.8269%2.7110%
PrimeNet2590.026762.7119%130002400000.00282.9978%0.029563.8297%1.1178%
GPU722630.554865.0794%160002800000.00341.8704%0.558265.7325%0.6531%
Difference+6+40.9449+3.0366%+4984000+199720000+1.7464+6.6322%+42.6913+5.0944%+5.0944%

Known prime factors (1 factor, 72.6 bits, 0.00252341% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
287681371270281487139926578072272.5941238702020032931
37 × 33478432973863
2021-11-253733478432973863481.47204,274381,527

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.197%
2009-07-03T00:57:00Carsten Kossendeyleela15000161250---0.003--0.617%
2010-12-24T02:50:00Jocelyn LaroucheManual testing2000020000---0.002--0.228%
2011-01-23T12:18:00Jocelyn LaroucheManual testing5000050000---0.006--0.466%
2011-09-27T22:44:00markrtiny1950004923750---0.051--3.058%
2017-06-28T04:14:53Jocelyn Larouchelow 4M39000039000006---0.065--3.206%
2019-10-23T02:43:10masserManual testing28800002880000012---0.481--5.898%
2020-03-05T14:29:39masserManual testing500000020000000012---1.750--8.503%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1997-11-11T00:00:00ANONYMOUSv4_computers21259--0.027--
2016-02-23T16:29:23Mark RoseManual testing259260--0.027--
2009-02-13T16:16:00Sturle Sundegopher.ifi260261--0.053--
2012-01-20T07:15:00markroldgamer261262--0.107--
2013-01-07T13:47:00dbaughManual testing262263--0.341--
2015-04-21T09:21:00VictordeHollanderManual testing263264--0.682--
2015-04-21T09:21:00VictordeHollanderManual testing264265--1.299--
2016-02-19T10:39:53YxinityManual testing265266--2.598--
2017-11-12T17:07:21Gordon SpenceManual testing266267--5.195--
2019-01-10T01:22:06chuenkitManual testing267268--10.39--
2021-05-19T10:49:34TJAOIManual testing268269--20.78--


ECM factoring results:

Old Calculation Method

Total ECM effort:9.523 GHz-days
Estimated T-Level:4.550
DigitsB1CurvesCompleteFacMiss
201100091 / 1000.91040.068%
255000091 / 2800.32572.211%

New Calculation Method

Total ECM effort:9.523 GHz-days
Estimated T-Level:4.550
DigitsB1CompleteFacMiss
20110002.9355.311%
25500000.26576.697%
302500000.01698.380%


ECM Summary

B1B2factorcurvesGHz-days
500005000000879.104
50000500000040.419


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-11-11T00:00:00ANONYMOUSv4_computers153D5AE7934D67__0.222
1999-05-16T00:00:00ANONYMOUSv4_computers893138841F5F735B0.222
1999-11-17T00:00:00ANONYMOUSv4_computers893138841F5F735B0.222
2018-09-23T06:15:05kkmrkkblmbrbkold893138841F5F735B0.222


PRP results:
dateuseridcompidcofactorsres64PRP
2021-12-01T18:45:15Poaotencent-CNsh
7127028148713992657807
6C3562485A50F350no


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 2880000, B2 = 28800000 (P-1 stage 2)
B1 = 2880000 (P-1 stage 1)
B1 = 390000, B2 = 3900000 (P-1 stage 2)
B1 = 195000, B2 = 4923750 (P-1 stage 2)
B1 = 390000 (P-1 stage 1)
B1 = 195000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 15000, B2 = 161250 (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: 2021-12-01T18:45:15+00:00