is 2 4209209 - 1
has 1267099 decimal digits
takes 0.525 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L2B3CFA4952C6C865double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual272227.200368.0556%620000015965654250158.370611.9911%385.571071.8861%3.8305%
PrimeNet2610.073062.2951%170003400000.00632.8357%0.079263.3643%1.0692%
GPU722651.733364.6154%220004500000.00821.8755%1.741565.2790%0.6637%
Difference+7+225.4671+3.4402%+6178000+15965204250+158.3624+10.1156%+383.8295+6.6070%+6.6070%

Known prime factors:
No known factors for M4209209

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2009-08-02T06:48:00Carsten Kossendeydurandal25000337500---0.008--0.645%
2011-08-11T02:41:00Squeeky_SquirrelT7500_220050000737500---0.016--1.025%
2011-12-06T17:16:00Squeeky_SquirrelP4_2600750001368750---0.026--1.360%
2015-07-24T05:36:00David Campeaui5-2500k114500030915000---0.500--4.395%
2022-04-06T12:05:14DRobinsonPEi3-9100620000015965654250---158.4--11.991%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-01-21T00:00:00schazv4_computers21260--0.036--
2001-09-16T00:00:00ANONYMOUSv4_computers21261--0.073--
2010-12-22T06:17:00markrManual testing261262--0.073--
2012-01-19T03:50:00GrunwalderGIMPManual testing21263--0.379--
2016-02-23T16:29:51Mark RoseManual testing262263--0.233--
2013-11-08T14:11:00JayderManual testing263264--0.466--
2013-11-19T00:42:00David CampeauManual testing264265--0.888--
2015-06-07T22:40:00snme2pm1Manual testing265266--1.775--
2017-12-27T17:44:16YxinityManual testing266267--3.551--
2018-12-15T14:25:30YxinityManual testing267268--7.101--
2018-11-12T01:10:17chuenkitManual testing267268--7.101--
2021-01-23T12:11:03-Anonymous-Manual testing268269--14.20--
2021-01-23T12:11:03-Anonymous-Manual testing269270--28.41--
2021-01-24T12:01:23-Anonymous-Manual testing270271--56.81--
2021-01-24T23:59:11-Anonymous-Manual testing271272--113.6--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.183 GHz-days
Estimated T-Level:0.600
DigitsB1CurvesCompleteFacMiss
201100012 / 1000.12088.638%
255000012 / 2800.04395.797%

New Calculation Method

Total ECM effort:2.183 GHz-days
Estimated T-Level:0.600
DigitsB1CompleteFacMiss
20110000.46263.031%
25500000.04395.819%
302500000.00399.731%


ECM Summary

B1B2factorcurvesGHz-days
500005000000122.183


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-03-03T00:00:00schazv4_computers2B3CFA4952C6C8650.525
1999-12-01T00:00:00ANONYMOUSv4_computers2B3CFA4952C6C8650.525


PRP results:
No PRP results for M4209209


P-1 factor-bounds graph:
B1 = 6200000, B2 = 15965654250 (P-1 stage 2)
B1 = 6200000 (P-1 stage 1)
B1 = 1145000, B2 = 30915000 (P-1 stage 2)
B1 = 1145000 (P-1 stage 1)
B1 = 75000, B2 = 1368750 (P-1 stage 2)
B1 = 50000, B2 = 737500 (P-1 stage 2)
B1 = 75000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 25000, B2 = 337500 (P-1 stage 2)
B1 = 25000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-04-06T12:05:14+00:00