is 2 1927789 - 1
has 580323 decimal digits
takes 0.105 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L1D6B9CE3F11ABEE9double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26715.413568.6567 %500000150000000.10155.1004 %15.514970.2554 %
Target2610.159365.5738 %110008500000.00451.8144 %0.163866.1984 %
Difference+6+15.2541+3.0829 %+489000+14150000+0.0970+3.2861%+15.3511+4.0570 %

Known prime factors (1 factor, 77.5 bits, 0.00401844% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
19277892088764478471170216722572477.46754175132197329952
25 × 3 × 149 × 857 × 4419383159
2015-03-25857441938315915,87718.94035.375

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2004-06-04ANONYMOUSv4_computers300000900000012--0.0617.816%
2016-03-17alpertronManual testing5000001500000012---8.914%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2002-12-09ANONYMOUSv4_computers212580.020
2010-02-09S485122USB-W2602610.080
2011-08-27GrunwalderGIMPManual testing212630.828


ECM factoring results:
Total ECM effort:19.711 GHz-days
Estimated T-Level:24.836
DigitsB1CompleteFacMiss
201100010.5100.003%
25500000.96738.011%
302500000.06194.046%
3510000000.00399.712%


ECM Summary

B1B2factorcurvesGHz-days
10.139
500005000000362.394
50000660000021216.62
50000675000070.555


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-01ANONYMOUSv4_computers1D6B9CE3F11ABEE90.105


PRP results:
dateuseridcompidcofactorsres64
2017-10-05Oliver KruseGTX-3
208876447847117021672257
E9743A2C9F631526
2017-11-10ATHec2-1xh
208876447847117021672257
E9743A2C9F631526


CERT results:
No CERT results for M1927789


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 300000, B2 = 9000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
B1 = 300000 (P-1 stage 1)
101
102
103
104
105
106
101
102
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
263
261
258
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=24.84 ~= 66-bit
250
260
270
280
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Last modified: 2024-02-29T14:28:04+00:00