is 2 3887557 - 1
has 1170272 decimal digits
takes 0.485 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LE424824DFDC33FE3double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual2677.643367.1642 %1000001303648501.30166.0370 %8.944969.1465 %
Target2640.915665.6250 %2400025000000.02872.2321 %0.944366.3923 %
Difference+3+6.7278+1.5392 %+76000+127864850+1.2729+3.8049%+8.0006+2.7542 %

Known prime factors (1 factor, 64.4 bits, 0.00165653% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
3887557243191444482714164412064.3993127818376460
22 × 5 × 49417 × 3164719
2012-09-274941731647191.49390.03960.0582

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2009-07-30Carsten Kossendeymother20000275000--0.0061.812%
2011-10-13Squeeky_SquirrelT7500_22007000011550006--0.0233.418%
2022-03-05JossManual testing9000090000--0.0141.471%
2022-03-22JossManual testing100000100000--0.0151.553%
2022-05-26JossManual testing100000130364850
skipped known factor: 24319144448271416441
--1.3028.153%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1998-05-08Bjørn Skogv4_computers212600.020
2009-02-24S485122USB-A2602610.040
2011-02-05markroldgamer2612620.079
2012-02-29GrunwalderGIMPManual testing212630.410


ECM factoring results:
Total ECM effort:0.506 GHz-days
Estimated T-Level:0.577
DigitsB1CompleteFacMiss
20110000.11589.102%
25500000.01198.938%


ECM Summary

B1B2factorcurvesGHz-days
10.151
50000500000030.355


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-05-08Bjørn Skogv4_computersE424824DFDC33FE30.485
1998-05-16Bjørn Skogv4_computersE424824DFDC33FE30.485
1998-06-07Bjørn Skogv4_computersE424824DFDC33FE30.485
1998-06-20Bjørn Skogv4_computersE424824DFDC33FE30.485
1998-07-11Bjørn Skogv4_computersE424824DFDC33FE30.485
1998-07-29Bjørn Skogv4_computersE424824DFDC33FE30.485
1999-10-29curtiscv4_computersE424824DFDC33FE30.485


PRP results:
dateuseridcompidcofactorsres64
2017-09-20kkmrkkblmbrbkManual testing
24319144448271416441
12E47D46C241FE1B
2017-12-26ATHec2-1xh
24319144448271416441
12E47D46C241FE1B


CERT results:
No CERT results for M3887557


P-1 factor-bounds graph:
B1 = 100000, B2 = 130364850 (P-1 stage 2)
B1 = 70000, B2 = 1155000 (P-1 stage 2)
B1 = 100000 (P-1 stage 1)
B1 = 90000 (P-1 stage 1)
B1 = 70000 (P-1 stage 1)
B1 = 20000, B2 = 275000 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
103
104
105
103
104
105
106
107
108
109
TF factor-bounds graph:
263
262
261
260
this exponent TF target: 64
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