is 2 8211397 - 1
has 2471877 decimal digits
takes 2.144 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LFA836143E3437E2Cdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual272116.464268.0556%1600000338657319070.43039.4920%186.894471.0877%3.0322%
PrimeNet2630.194463.4921%360009000000.03153.6206%0.225864.8139%1.3218%
GPU722673.618665.6716%5500013000000.04652.6270%3.665166.5735%0.9018%
Difference+5+112.8456+2.3839%+1545000+3385273190+70.3837+6.8650%+183.2293+4.5143%+4.5143%

Known prime factors:
No known factors for M8211397

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-08-03T00:00:00Team Prime Ribv4_computers45000697500---0.030--1.104%
2002-08-10T00:00:00Team Prime Ribv4_computers45000753750---0.032--1.128%
2012-10-28T17:17:00NesowaEPC950001638750---0.068--1.687%
2020-03-01T01:54:48harleei5-5250U_16004750001615000012---0.503--3.762%
2022-01-29T19:17:43axnManual testing16000003386573190---70.43--9.492%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-09-20T00:00:00ANONYMOUSv4_computers21262--0.075--
1999-03-01T00:00:00ANONYMOUSv4_computers21263--0.194--
2011-08-11T05:14:00Carsten KossendeyManual testing263264--0.239--
2013-12-28T17:13:00David CampeauManual testing264265--0.455--
2015-06-03T12:35:00VictordeHollanderManual testing265266--0.910--
2015-12-10T21:02:46snme2pm1Manual testing266267--1.820--
2018-07-16T02:15:46chuenkitManual testing267268--3.640--
2020-02-07T10:40:50TJAOIManual testing268269--7.280--
2021-08-19T16:19:46SRBaseManual testing269270--14.56--
2021-08-22T15:18:50krackerManual testing270271--29.12--
2021-10-05T16:23:28SRBaseManual testing271272--58.24--


ECM factoring results:

Old Calculation Method

Total ECM effort:1.191 GHz-days
Estimated T-Level:0.150
DigitsB1CurvesCompleteFacMiss
20110003 / 1000.03097.030%
25500003 / 2800.01198.932%

New Calculation Method

Total ECM effort:1.191 GHz-days
Estimated T-Level:0.150
DigitsB1CompleteFacMiss
20110000.11589.102%
25500000.01198.938%


ECM Summary

B1B2factorcurvesGHz-days
50000500000031.191


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2000-01-12T00:00:00ANONYMOUSv4_computersFA836143E3437E2C2.144
2003-03-27T00:00:00Team Prime Ribv4_computersFA836143E3437E2C2.144


PRP results:
No PRP results for M8211397


P-1 factor-bounds graph:
B1 = 1600000, B2 = 3386573190 (P-1 stage 2)
B1 = 1600000 (P-1 stage 1)
B1 = 475000, B2 = 16150000 (P-1 stage 2)
B1 = 475000 (P-1 stage 1)
B1 = 95000, B2 = 1638750 (P-1 stage 2)
B1 = 95000 (P-1 stage 1)
B1 = 45000, B2 = 753750 (P-1 stage 2)
B1 = 45000, B2 = 697500 (P-1 stage 2)
B1 = 45000 (P-1 stage 1)
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1010
TF factor-bounds graph:
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270
269
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250
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2100
Last modified: 2022-01-29T19:17:43+00:00