is 2 1657247 - 1
has 498882 decimal digits
takes 0.078 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LFCD7DD5C793E7CD4double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26717.929768.6567 %500000150000000.08805.0083 %18.017770.2265 %
Target2610.185465.5738 %70003500000.00181.1522 %0.187165.9704 %
Difference+6+17.7443+3.0829 %+493000+14650000+0.0863+3.8561%+17.8306+4.2561 %

Known prime factors (1 factor, 63.0 bits, 0.00380171% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
165724792474725276684961031963.0042790010338733
19 × 146842649407
2008-05-27191468426494070.9631545.951,019.7

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-03-17alpertronManual testing5000001500000012---8.770%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1998-11-07Stephen Woodv4_computers212570.012
2003-05-04ANONYMOUSv4_computers212580.023


ECM factoring results:
Total ECM effort:38.169 GHz-days
Estimated T-Level:25.717
DigitsB1CompleteFacMiss
201100014.6150.000%
25500001.67118.807%
302500000.14386.643%
3510000000.01099.006%


ECM Summary

B1B2factorcurvesGHz-days
10.042
50000500000025017.03
250000400000005021.10


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-11-28Stephen Woodv4_computersFCD7DD5C793E7CD40.078


PRP results:
dateuseridcompidcofactorsres64
2017-10-02Oliver KruseGTX-0
9247472527668496103
1F883B28ED34B335
2017-11-02kkmrkkblmbrbkold
9247472527668496103
1F883B28ED34B335


CERT results:
No CERT results for M1657247


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
100
101
102
103
104
105
106
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
TF factor-bounds graph:
258
257
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.72 ~= 69-bit
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Last modified: 2024-02-09T03:30:02+00:00