is 2 2818687 - 1
has 848510 decimal digits
takes 0.218 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L30D65A9726CCE9A8double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26942.355568.1159%50000002000000001.74988.4862%44.105270.8217%2.7058%
PrimeNet2590.027262.7119%120002400000.00272.9306%0.030063.8046%1.0928%
GPU722630.566265.0794%150002600000.00321.7920%0.569465.7051%0.6258%
Difference+6+41.7892+3.0366%+4985000+199740000+1.7466+6.6942%+43.5358+5.1166%+5.1166%

Known prime factors (1 factor, 88.1 bits, 0.00312530% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28186873299330200931042932146982492788.09258526012305215920252
22 × 43 × 2411 × 141131278889431
2021-09-18241114113127888943130,480,482861,1341,608,359

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.196%
2016-09-14T01:53:47Jocelyn Larouchelow 4M13504833000006---0.034--2.612%
2016-09-21T12:09:26Jocelyn Larouchelow 4M1350483630000---0.036--2.668%
2016-12-21T00:33:38Jocelyn Larouchelow 4M194468194468---0.022--1.064%
2017-01-10T10:25:18Jocelyn Larouchelow 4M233361233361---0.026--1.170%
2017-03-17T00:52:40Jocelyn Larouchelow 4M33603933603906---0.056--3.029%
2018-09-03T21:22:26Jocelyn Larouchelow 4M499246499246---0.056--1.681%
2019-06-27T13:59:16BigBrotherWinston10000003000000012---0.289--5.421%
2019-09-28T03:14:01masserManual testing28186872818687012---0.470--5.852%
2020-01-19T15:04:42masserManual testing500000020000000012---1.750--8.486%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:22Mark RoseManual testing21260--0.054--
2009-02-13T04:32:00Sturle Sundefizir.ifi260261--0.054--
2012-02-23T12:04:00Grant McCrackenthumper261262--0.109--
2013-01-10T10:21:00dbaughManual testing262263--0.348--
2015-04-21T09:19:00VictordeHollanderManual testing263264--0.697--
2015-04-21T09:19:00VictordeHollanderManual testing264265--1.326--
2016-02-12T10:12:11ramgeisManual testing265266--2.651--
2017-10-24T17:48:50Gordon SpenceManual testing266267--5.302--
2019-01-02T03:46:01chuenkitManual testing267268--10.60--
2021-05-19T10:49:42TJAOIManual testing268269--21.21--


ECM factoring results:

Old Calculation Method

Total ECM effort:10.644 GHz-days
Estimated T-Level:21.804
DigitsB1CurvesCompleteFacMiss
2011000101 / 1001.01036.237%
2550000101 / 2800.36169.673%

New Calculation Method

Total ECM effort:10.644 GHz-days
Estimated T-Level:21.804
DigitsB1CompleteFacMiss
20110003.2743.787%
25500000.29674.364%
302500000.01898.192%


ECM Summary

B1B2factorcurvesGHz-days
500005000000939.70
50000500000010.104
50000675000070.841


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-16T00:00:00ANONYMOUSv4_computers30D65A9726CCE9A80.218
2018-09-06T14:23:29kkmrkkblmbrbkold30D65A9726CCE9A80.218


PRP results:
dateuseridcompidcofactorsres64PRP
2021-09-19T05:23:47DrDerpenbergMain
329933020093104293214698249
4F020F306E4BD6F2no
2021-09-19T05:38:15SRJ2877LTOS
329933020093104293214698249
4F020F306E4BD6F2no


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 2818687, B2 = 28186870 (P-1 stage 2)
B1 = 2818687 (P-1 stage 1)
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 336039, B2 = 3360390 (P-1 stage 2)
B1 = 499246 (P-1 stage 1)
B1 = 336039 (P-1 stage 1)
B1 = 135048, B2 = 3630000 (P-1 stage 2)
B1 = 135048, B2 = 3300000 (P-1 stage 2)
B1 = 233361 (P-1 stage 1)
B1 = 194468 (P-1 stage 1)
B1 = 135048 (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: 2021-09-19T05:38:15+00:00