is 2 2121653 - 1
has 638682 decimal digits
takes 0.139 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP143144D71EEEC0E0verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26828.093667.6471%25000001250000000.87467.9064%28.968270.2050%2.5580%
PrimeNet2580.018162.0690%90001600000.00162.6829%0.019763.0866%1.0177%
GPU722620.289664.5161%100001400000.00161.4543%0.291265.0322%0.5161%
Difference+6+27.8040+3.1309%+2490000+124860000+0.8730+6.4521%+28.6770+5.1728%+5.1728%

Known prime factors (1 factor, 70.2 bits, 0.00330715% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
212165313248088715612576864412270.166312211485940740
22 × 3 × 5 × 43 × 121012203853
2020-09-2943121012203853125.80628.571,174.0

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-07-30T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.224%
2009-08-03T13:06:00harleeP4_260020000265000---0.003--0.884%
2011-01-01T00:56:00Jocelyn LaroucheManual testing3000030000---0.003--0.352%
2011-01-11T22:55:00Jocelyn LaroucheManual testing5000050000---0.005--0.511%
2011-01-24T00:18:00James Heinrichi7-9201400003045000---0.028--2.777%
2016-06-24T05:32:51Jocelyn LaroucheManual testing210000609000012---0.051--3.462%
2017-08-19T15:19:13Jocelyn Larouchelow 4M42000042000006---0.060--3.509%
2017-08-24T06:45:22mikrMSI250000012500000012---0.875--7.906%
2017-08-30T00:32:07Jocelyn Larouchelow 4M50400050400006---0.072--3.735%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-01-17T00:00:00ANONYMOUSv4_computers21258--0.018--
2016-02-23T16:29:05Mark RoseManual testing258260--0.054--
2009-01-03T04:24:00Sturle Sundegobi.ifi260261--0.072--
2012-04-02T17:47:00Sebastian HornbostelManual testing261262--0.145--
2013-09-06T08:31:00ramgeisManual testing262263--0.463--
2015-03-15T12:13:00VictordeHollanderManual testing263264--0.925--
2015-03-15T12:13:00VictordeHollanderManual testing264265--1.761--
2015-10-21T19:11:16omylistManual testing265266--3.522--
2016-10-15T17:13:25Gordon SpenceManual testing266267--7.044--
2019-05-06T12:23:36TJAOIManual testing267268--14.09--


ECM factoring results:

Old Calculation Method

Total ECM effort:10.907 GHz-days
Estimated T-Level:22.286
DigitsB1CurvesCompleteFacMiss
2011000128 / 1001.28027.625%
2550000128 / 2800.45763.257%

New Calculation Method

Total ECM effort:10.907 GHz-days
Estimated T-Level:22.286
DigitsB1CompleteFacMiss
20110004.1291.610%
25500000.37368.854%
302500000.02397.728%
3510000000.00199.895%


ECM Summary

B1B2factorcurvesGHz-days
50000500000012110.31
50000500000070.596


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2015-11-14T18:08:37MadPooManual testingCBA73589B218CB__0.139


PRP results:
dateuseridcompidcofactorsres64PRP
2020-09-29T07:31:03ATHec2-PRPCF
1324808871561257686441
143144D71EEEC0E0no


P-1 factor-bounds graph:
B1 = 2500000, B2 = 125000000 (P-1 stage 2)
B1 = 2500000 (P-1 stage 1)
B1 = 504000, B2 = 5040000 (P-1 stage 2)
B1 = 420000, B2 = 4200000 (P-1 stage 2)
B1 = 210000, B2 = 6090000 (P-1 stage 2)
B1 = 504000 (P-1 stage 1)
B1 = 420000 (P-1 stage 1)
B1 = 140000, B2 = 3045000 (P-1 stage 2)
B1 = 210000 (P-1 stage 1)
B1 = 140000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 20000, B2 = 265000 (P-1 stage 2)
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: 2020-09-29T07:31:03+00:00