is 2 2148877 - 1
has 646877 decimal digits
takes 0.141 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L663546FC9DD8DD5Ddouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26827.737767.6471%25000001250000000.87467.9165%28.612370.2083%2.5612%
PrimeNet2580.017962.0690%90001700000.00172.7335%0.019663.1058%1.0368%
GPU722620.285964.5161%100001600000.00171.5176%0.287665.0546%0.5385%
Difference+6+27.4518+3.1309%+2490000+124840000+0.8729+6.3988%+28.3247+5.1536%+5.1536%

Known prime factors (1 factor, 69.3 bits, 0.00322643% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
21488777430242540598253314572169.332172886641268864
27 × 29 × 73 × 638014589
2020-07-21128638014589111.013.31406.1896

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-03-07T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.225%
2010-11-03T21:25:00Jocelyn LaroucheManual testing2000020000---0.002--0.254%
2010-12-30T22:20:00Jocelyn LaroucheManual testing3000030000---0.003--0.353%
2011-01-13T23:58:00Jocelyn LaroucheManual testing5000050000---0.005--0.513%
2011-01-22T07:03:00James Heinrichi7-9201350002666250---0.026--2.681%
2016-04-29T05:18:09Jocelyn LaroucheManual testing270000995915712---0.076--3.982%
2017-10-04T07:45:21Jocelyn Larouchelow 4M54000054000006---0.077--3.829%
2017-11-17T22:14:10Jocelyn Larouchelow 4M6480001095507212---0.115--4.546%
2017-11-30T06:36:33mikrMSI250000012500000012---0.875--7.916%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-01-29T00:00:00ANONYMOUSv4_computers21258--0.018--
2016-02-23T16:29:07Mark RoseManual testing258260--0.054--
2009-01-04T20:48:00Sturle Sundegolan.ifi260261--0.071--
2009-01-07T08:25:00Sturle Sundejodel.ifi261262--0.143--
2013-09-07T11:35:00ramgeisManual testing262263--0.457--
2015-03-18T10:56:00VictordeHollanderManual testing263264--0.914--
2015-03-18T10:56:00VictordeHollanderManual testing264265--1.739--
2015-12-30T18:01:32ramgeisManual testing265266--3.478--
2016-10-29T15:24:12Gordon SpenceManual testing266267--6.955--
2019-04-08T13:40:41TJAOIManual testing267268--13.91--


ECM factoring results:

Old Calculation Method

Total ECM effort:8.535 GHz-days
Estimated T-Level:21.786
DigitsB1CurvesCompleteFacMiss
2011000100 / 1001.00036.603%
2550000100 / 2800.35769.923%

New Calculation Method

Total ECM effort:8.535 GHz-days
Estimated T-Level:21.786
DigitsB1CompleteFacMiss
20110003.2263.972%
25500000.29274.711%
302500000.01898.221%


ECM Summary

B1B2factorcurvesGHz-days
500005000000998.449
50000500000010.085


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-15T00:00:00ANONYMOUSv4_computers663546FC9DD8DD5D0.141
2018-04-08T22:47:14kkmrkkblmbrbkold663546FC9DD8DD5D0.141


PRP results:
dateuseridcompidcofactorsres64PRP
2020-07-22T08:27:45James HeinrichC2750
743024254059825331457
392AC608C9AB3C7Eno
2020-07-22T08:39:56ATHec2-PRPCFDC
743024254059825331457
392AC608C9AB3C7Eno


P-1 factor-bounds graph:
B1 = 2500000, B2 = 125000000 (P-1 stage 2)
B1 = 2500000 (P-1 stage 1)
B1 = 648000, B2 = 10955072 (P-1 stage 2)
B1 = 540000, B2 = 5400000 (P-1 stage 2)
B1 = 270000, B2 = 9959157 (P-1 stage 2)
B1 = 648000 (P-1 stage 1)
B1 = 540000 (P-1 stage 1)
B1 = 135000, B2 = 2666250 (P-1 stage 2)
B1 = 270000 (P-1 stage 1)
B1 = 135000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 20000 (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: 2020-07-22T08:39:56+00:00