is 2 2817709 - 1
has 848215 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-L618DDD186E1AECE2double-checked
PRP159E3ED4060AF781verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26942.370268.1159%50000002000000001.74988.4860%44.119970.8216%2.7057%
PrimeNet2590.027362.7119%120002400000.00272.9304%0.030063.8046%1.0927%
GPU722630.566465.0794%150002600000.00321.7919%0.569665.7051%0.6257%
Difference+6+41.8037+3.0366%+4985000+199740000+1.7466+6.6941%+43.5504+5.1165%+5.1165%

Known prime factors (1 factor, 77.1 bits, 0.00273704% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28177091644378294225233956581772477.12229179349148993632
25 × 115589 × 7888766759
2021-09-22115589788876675912,06748.14789.902

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.196%
2016-09-13T03:53:09Jocelyn Larouchelow 4M13505633000006---0.034--2.612%
2016-09-21T12:09:26Jocelyn Larouchelow 4M1350563630000---0.036--2.668%
2016-12-21T00:33:38Jocelyn Larouchelow 4M194480194480---0.022--1.064%
2017-01-10T10:25:18Jocelyn Larouchelow 4M233376233376---0.026--1.170%
2017-03-17T00:52:41Jocelyn Larouchelow 4M33606133606106---0.056--3.028%
2018-09-03T21:22:26Jocelyn Larouchelow 4M499273499273---0.056--1.681%
2019-10-03T23:34:07masserManual testing28177092817709012---0.470--5.851%
2020-01-19T15:04:42masserManual testing500000020000000012---1.750--8.486%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:22Mark RoseManual testing21260--0.055--
2009-02-12T22:15:00Sturle Sundefizir.ifi260261--0.055--
2012-02-22T09:25:00Grant 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--
2016-02-12T10:12:10ramgeisManual testing265266--2.652--
2017-10-24T17:48:50Gordon SpenceManual testing266267--5.304--
2019-01-01T23:16:49chuenkitManual testing267268--10.61--
2021-05-19T10:49:44TJAOIManual testing268269--21.22--


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)
1999-08-07T00:00:00ANONYMOUSv4_computers618DDD186E1AECE20.218
2018-09-06T07:26:58kkmrkkblmbrbkold618DDD186E1AECE20.218


PRP results:
dateuseridcompidcofactorsres64PRP
2021-09-27T09:00:00MarkSdesktop-i7
164437829422523395658177
159E3ED4060AF781no


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 2817709, B2 = 28177090 (P-1 stage 2)
B1 = 2817709 (P-1 stage 1)
B1 = 336061, B2 = 3360610 (P-1 stage 2)
B1 = 499273 (P-1 stage 1)
B1 = 336061 (P-1 stage 1)
B1 = 135056, B2 = 3630000 (P-1 stage 2)
B1 = 135056, B2 = 3300000 (P-1 stage 2)
B1 = 233376 (P-1 stage 1)
B1 = 194480 (P-1 stage 1)
B1 = 135056 (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: 2021-09-27T09:00:00+00:00