is 2 3912221 - 1
has 1177696 decimal digits
takes 0.488 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LF63E8A9CE487399Adouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual2677.595267.1642 %1000001303648501.30166.0420 %8.896769.1481 %
Target2640.909865.6250 %2600025000000.02912.2792 %0.938966.4085 %
Difference+3+6.6854+1.5392 %+74000+127864850+1.2725+3.7628%+7.9579+2.7396 %

Known prime factors (1 factor, 61.4 bits, 0.00156991% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
391222130814086840317881371961.418393818330308
22 × 13 × 257 × 29468597
2009-10-14257294685970.14430.29040.5423

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2009-07-10Carsten Kossendeymother20000285000--0.0061.832%
2022-03-04JossManual testing9000090000--0.0141.472%
2022-03-22JossManual testing100000100000--0.0161.554%
2022-05-26JossManual testing100000130364850
skipped known factor: 3081408684031788137
--1.3028.159%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1998-02-24ANONYMOUSv4_computers212600.020
2008-12-26Architects Cubedm1_fw2602610.039


ECM factoring results:
Total ECM effort:0.355 GHz-days
DigitsB1CompleteFacMiss


ECM Summary

B1B2factorcurvesGHz-days
10.355


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-07-05ANONYMOUSv4_computersF63E8A9CE487399A0.488
1999-09-30ANONYMOUSv4_computersF63E8A9CE487399A0.488


PRP results:
dateuseridcompidcofactorsres64
2017-09-20kkmrkkblmbrbkManual testing
3081408684031788137
9C4DC4B4DFA0DB12
2017-12-29Oliver KruseGTX-6
3081408684031788137
9C4DC4B4DFA0DB12


CERT results:
No CERT results for M3912221


P-1 factor-bounds graph:
B1 = 100000, B2 = 130364850 (P-1 stage 2)
B1 = 100000 (P-1 stage 1)
B1 = 90000 (P-1 stage 1)
B1 = 20000, B2 = 285000 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
101
102
103
104
105
101
102
103
104
105
106
107
108
109
TF factor-bounds graph:
261
260
this exponent TF target: 64
TF double-checked to: 67
250
260
270
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Last modified: 2024-03-13T02:15:48+00:00