is 2 2874941 - 1
has 865444 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-L526D3118FD231296double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26820.732667.6471%50000002000000001.74989.1807%22.482370.6173%2.9702%
PrimeNet2590.026762.7119%130002400000.00282.9975%0.029663.8296%1.1177%
GPU722630.555165.0794%160002800000.00341.8702%0.558665.7324%0.6531%
Difference+5+20.1774+2.5677%+4984000+199720000+1.7464+7.3106%+21.9238+4.8849%+4.8849%

Known prime factors (1 factor, 75.9 bits, 0.00263852% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2874941683732494002499064853912375.85611891243924701395
3 × 5 × 31 × 173 × 147818309711
2021-04-201731478183097115,159.0901.941,684.6

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.245%
2009-07-03T00:56:00Carsten Kossendeyleela15000161250---0.003--0.723%
2010-12-23T00:29:00Jocelyn LaroucheManual testing2000020000---0.002--0.272%
2011-01-22T22:18:00Jocelyn LaroucheManual testing5000050000---0.006--0.544%
2011-02-07T10:45:00markrtiny1250002812500---0.030--2.793%
2016-09-17T03:20:36Jocelyn Larouchelow 4M16637530937506---0.036--3.000%
2016-12-21T00:33:39Jocelyn Larouchelow 4M199650199650---0.022--1.234%
2017-04-13T02:13:58Jocelyn Larouchelow 4M33275033275006---0.056--3.365%
2018-01-22T19:54:02Jocelyn Larouchelow 4M574992574992---0.064--2.015%
2018-09-03T21:22:22Jocelyn Larouchelow 4M73999014799806---0.087--2.872%
2018-09-05T22:38:04Jocelyn Larouchelow 4M73999022199704---0.092--3.250%
2018-09-12T23:00:20Jocelyn Larouchelow 4M7399903699950---0.101--3.731%
2019-10-23T02:43:09masserManual testing28800002880000012---0.481--6.428%
2020-03-03T02:34:23masserManual testing500000020000000012---1.750--9.181%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-04-21T00:00:00ANONYMOUSv4_computers21259--0.027--
2016-02-23T16:29:23Mark RoseManual testing259260--0.027--
2009-02-12T06:13:00Sturle Sundegopher.ifi260261--0.053--
2012-01-22T04:52:00markroldgamer261262--0.107--
2013-01-07T13:47:00dbaughManual testing262263--0.341--
2015-04-21T09:21:00VictordeHollanderManual testing263264--0.683--
2015-04-21T09:21:00VictordeHollanderManual testing264265--1.300--
2016-02-19T04:21:38YxinityManual testing265266--2.599--
2017-11-12T17:07:20Gordon SpenceManual testing266267--5.199--
2019-01-09T01:10:00chuenkitManual testing267268--10.40--


ECM factoring results:

Old Calculation Method

Total ECM effort:8.358 GHz-days
Estimated T-Level:3.950
DigitsB1CurvesCompleteFacMiss
201100079 / 1000.79045.204%
255000079 / 2800.28275.379%

New Calculation Method

Total ECM effort:8.358 GHz-days
Estimated T-Level:3.950
DigitsB1CompleteFacMiss
20110002.5647.700%
25500000.23279.311%
302500000.01498.582%


ECM Summary

B1B2factorcurvesGHz-days
500005000000666.906
50000500000060.628
50000645000070.825


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-06-01T00:00:00ANONYMOUSv4_computers526D3118FD2312960.222
1999-07-27T00:00:00ANONYMOUSv4_computers526D3118FD2312960.222
2018-09-22T19:05:58kkmrkkblmbrbkold526D3118FD2312960.222


PRP results:
dateuseridcompidcofactorsres64PRP
2021-04-24T07:22:35Klaus Nordmannno1
68373249400249906485391
76E28806BE638F__no
2021-04-30T19:13:50Kirill Frolovshodan1
68373249400249906485391
76E28806BE638F91no


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 = 739990, B2 = 3699950 (P-1 stage 2)
B1 = 739990, B2 = 2219970 (P-1 stage 2)
B1 = 739990, B2 = 1479980 (P-1 stage 2)
B1 = 739990 (P-1 stage 1)
B1 = 574992 (P-1 stage 1)
B1 = 332750, B2 = 3327500 (P-1 stage 2)
B1 = 332750 (P-1 stage 1)
B1 = 166375, B2 = 3093750 (P-1 stage 2)
B1 = 125000, B2 = 2812500 (P-1 stage 2)
B1 = 199650 (P-1 stage 1)
B1 = 166375 (P-1 stage 1)
B1 = 125000 (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: 2021-04-30T19:13:50+00:00