is 2 1648391 - 1
has 496216 decimal digits
takes 0.078 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
Actual26718.026068.6567 %500000150000000.08805.0051 %18.114070.2255 %
Target2610.186465.5738 %65004000000.00191.1718 %0.188365.9772 %
Difference+6+17.8397+3.0829 %+493500+14600000+0.0861+3.8333%+17.9258+4.2483 %

Known prime factors (3 factors, 152.2 bits, 0.00923295% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
164839113187129823.6534
22
-446.785e-132.730e-75.555e-7
164839125465289025721211651.177772428660
22 × 3 × 5 × 17 × 19 × 39857
2014-06-1919398570.00020.00010.0003
16483911946171562301055725784232477.36559032461421503021
3 × 41 × 5059 × 161753 × 586501
2015-05-1816175358650125,6460.01260.0225

4 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2015-05-18alpertronManual testing500000150000001222477.3650.1018.765%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2014-06-19TJAOIManual testing??
51.177
16
2.01836e-6


ECM factoring results:
Total ECM effort:38.152 GHz-days
Estimated T-Level:25.718
DigitsB1CompleteFacMiss
201100014.6540.000%
25500001.67418.740%
302500000.14486.623%
3510000000.01099.005%


ECM Summary

B1B2factorcurvesGHz-days
50000500000025117.07
250000400000005021.08


Lucas-Lehmer results:
No L-L results for M1648391


PRP results:
dateuseridcompidcofactorsres64
2017-10-02Oliver KruseGTX-0
13187129
2546528902572121
194617156230105572578423
E1917F5FA66580C6
2017-10-04kkmrkkblmbrbkManual testing
13187129
2546528902572121
194617156230105572578423
E1917F5FA66580C6
2017-11-14ATHec2-1xh
13187129
2546528902572121
194617156230105572578423
E1917F5FA66580C6


CERT results:
No CERT results for M1648391


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
TF factor-bounds graph:
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.72 ~= 69-bit
250
260
270
280
JSON version of this page
Last modified: 2024-03-13T02:15:48+00:00