is 2 3974221 - 1
has 1196360 decimal digits
takes 0.496 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LB3D49D47071FA776double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual2677.476767.1642 %10000001130976001.28548.2943 %8.762069.8877 %
Target2651.835866.1538 %2000018000000.02121.7014 %1.856966.7297 %
Difference+2+5.6409+1.0103 %+980000+111297600+1.2642+6.5929%+6.9051+3.1580 %

Known prime factors (1 factor, 62.0 bits, 0.00156102% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
397422147363793537062213591962.038595887766899
3 × 29 × 31 × 4481 × 49307
2009-07-274481493070.18550.00130.0016

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2009-07-27Carsten Kossendeymother1962.0380.0060.000%
2022-04-19JossManual testing300000300000
skipped known factor: 4736379353706221359
--0.0482.287%
2022-05-11JossManual testing500000113097600
skipped known factor: 4736379353706221359
--1.2679.138%
2022-09-29JossManual testing1000000113097600
skipped known factor: 4736379353706221359
--1.3579.791%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1998-01-05ANONYMOUSv4_computers212600.019
2001-08-26ANONYMOUSv4_computers212610.039


ECM factoring results:
Total ECM effort:0.475 GHz-days
Estimated T-Level:0.577
DigitsB1CompleteFacMiss
20110000.11589.102%
25500000.01198.938%


ECM Summary

B1B2factorcurvesGHz-days
50000500000030.475


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-01-13ANONYMOUSv4_computersB3D49D47071FA7760.496
1998-07-21ANONYMOUSv4_computersB3D49D47071FA7760.496
1999-10-07ANONYMOUSv4_computersB3D49D47071FA7760.496


PRP results:
dateuseridcompidcofactorsres64
2017-09-20kkmrkkblmbrbkManual testing
4736379353706221359
60FF8B699F5E1AB9
2018-01-02Oliver KruseGTX-5
4736379353706221359
60FF8B699F5E1AB9


CERT results:
No CERT results for M3974221


P-1 factor-bounds graph:
B1 = 1000000, B2 = 113097600 (P-1 stage 2)
B1 = 500000, B2 = 113097600 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 500000 (P-1 stage 1)
B1 = 300000 (P-1 stage 1)
102
103
104
105
106
102
103
104
105
106
107
108
109
TF factor-bounds graph:
261
260
this exponent TF target: 65
TF double-checked to: 67
ECM T-Level=0.58 ~= -15-bit
250
260
270
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Last modified: 2024-03-13T02:15:48+00:00