is 2 2081437 - 1
has 626575 decimal digits
takes 0.137 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LC95D157CA9019262double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26957.357969.5652%1430000048385326990252.614516.1331%309.972474.4753%
Target2620.295266.1290%90007000000.00441.3991%0.299666.6029%
Difference+7+57.0627+3.4362%+14291000+48384626990+252.6101+14.7340%+309.6728+7.8724%

Known prime factors:
No known factors for M2081437

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-02-27ANONYMOUSv4_computers2048204800---0.001--0.179%
2009-07-25harleeP4_260020000260000---0.003--0.751%
2010-12-28Jocelyn LaroucheManual testing3000030000---0.003--0.297%
2011-01-07Jocelyn LaroucheManual testing5000050000---0.005--0.435%
2011-01-22James HeinrichQ66001350003105000---0.028--2.462%
2016-07-17Jocelyn LaroucheManual testing182420621000012---0.049--3.034%
2016-11-04Jocelyn Larouchelow 4M218904218904---0.021--1.075%
2016-11-06Jocelyn Larouchelow 4M262684262684---0.025--1.181%
2016-11-11Jocelyn Larouchelow 4M315220315220---0.030--1.294%
2017-03-31mikrMSI250000012500000012---0.875--7.267%
2017-05-13Jocelyn Larouchelow 4M39026439026406---0.055--3.072%
2023-01-18Jocelyn LaroucheManual testing1000000710870160---3.783--8.348%
2023-03-17Jocelyn LaroucheManual testing10000002049006960---10.73--9.433%
2023-07-07JossJoss10000004725280560---24.63--10.300%
2023-08-19Sid & AndyHockey_Puck1430000048385326990---252.6--16.133%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-01-10ANONYMOUSv4_computers21258--0.018--
2016-02-23Mark RoseManual testing258260--0.055--
2009-01-02Sturle Sundekinner.ifi260261--0.074--
2012-03-17Sebastian HornbostelManual testing261262--0.148--
2013-09-02ramgeisManual testing262263--0.472--
2015-03-31VictordeHollanderManual testing263264--0.943--
2015-03-31VictordeHollanderManual testing264265--1.795--
2015-11-05ramgeisManual testing265266--3.590--
2016-09-14Gordon SpenceManual testing266267--7.180--
2019-04-01chuenkitManual testing267268--14.36--
2021-08-26TJAOIManual testing268269--28.72--


ECM factoring results:
Total ECM effort:17.670 GHz-days
Estimated T-Level:23.677
DigitsB1CompleteFacMiss
20110007.9350.036%
25500000.73547.934%
302500000.04795.456%
3510000000.00299.782%


ECM Summary

B1B2factorcurvesGHz-days
50000500000019716.75
50000675000070.680
766202417689010.245


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Rhesa RozendaalC95D157CA90192620.137
1999-02-07ANONYMOUSv4_computersC95D157CA90192620.137
2017-06-09kkmrkkblmbrbkc4.largeC95D157CA90192620.137


PRP results:
No PRP results for M2081437


P-1 factor-bounds graph:
B1 = 14300000, B2 = 48385326990 (P-1 stage 2)
B1 = 1000000, B2 = 4725280560 (P-1 stage 2)
B1 = 1000000, B2 = 2049006960 (P-1 stage 2)
B1 = 1000000, B2 = 710870160 (P-1 stage 2)
B1 = 14300000 (P-1 stage 1)
B1 = 2500000, B2 = 125000000 (P-1 stage 2)
B1 = 2500000 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
B1 = 390264, B2 = 3902640 (P-1 stage 2)
B1 = 182420, B2 = 6210000 (P-1 stage 2)
B1 = 390264 (P-1 stage 1)
B1 = 315220 (P-1 stage 1)
B1 = 135000, B2 = 3105000 (P-1 stage 2)
B1 = 262684 (P-1 stage 1)
B1 = 218904 (P-1 stage 1)
B1 = 182420 (P-1 stage 1)
B1 = 135000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 20000, B2 = 260000 (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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266
265
264
263
262
261
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258
this exponent TF target: 62
TF double-checked to: 67.9
ECM T-Level=23.68 ~= 62-bit
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Last modified: 2023-10-02T12:12:48+00:00