is 2 21878869 - 1
has 6586196 decimal digits
takes 15.953 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual27010.921564.2857 %----10.921564.2857 %
Target2695.456763.7681 %160000250000001.60013.9274 %7.056865.1911 %
Difference+1+5.4648+0.5176 %-160000-25000000-1.6001-3.9274 %+3.8648-0.9054 %

Known prime factors (5 factors, 222.4 bits, 0.00101629% known):
Remaining cofactor is PRP status unknown

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2187886935006190411031.70580
24 × 5
2011-06-2416161.330e-111.692e-53.443e-5
218788695308688774171238.95012132
22 × 32 × 337
2008-09-0893372.721e-92.841e-53.641e-5
21878869166888512112971443.924381392
24 × 112 × 197
2008-10-011211978.314e-80.00010.0003
218788697696068952011531549.45117587904
26 × 274811
2011-06-24642748116.532e-60.01590.0296
218788693606810055594394631858.3248242679399
8242679399
2015-08-26182426793990.0031474.81886.82

26 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2011-06-24AxonManual testing2581.1560.9410.000%


Trial Factoring results:
5758596061626364656667686970
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2008-09-08Will EdgingtonManual testing??
38.950
12
2008-10-01markrManual testing??
43.924
14
2015-08-26TJAOIManual testing258259*
58.324
18
0.001
2023-01-29LordJuliusManual testing267270


ECM factoring results:
No ECM results for M21878869


Lucas-Lehmer results:
No L-L results for M21878869


PRP results:
No PRP results for M21878869


CERT results:
No CERT results for M21878869


P-1 factor-bounds graph:
100
101
102
103
100
101
102
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
270
this exponent TF target: 69
TF double-checked to: 67
250
260
270
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Last modified: 2024-03-13T02:15:48+00:00