is 2 1616623 - 1
has 486653 decimal digits
takes 0.072 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L8674760A8AD7857Adouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26718.380268.6567 %500000150000000.08354.9934 %18.463870.2218 %
Target2610.190065.5738 %65003000000.00151.0588 %0.191565.9383 %
Difference+6+18.1902+3.0829 %+493500+14700000+0.0821+3.9346%+18.2723+4.2835 %

Known prime factors (2 factors, 134.3 bits, 0.00830927% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1616623977081932189985230812066.40530219845077980
22 × 32 × 5 × 273149 × 614639
2008-04-102731496146399.13540.01890.0360
16166232800887194535063322632167.92486627716991997
3 × 127 × 21179 × 10735603
2015-04-25211791073560318.3800.03920.0708

1 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2002-04-14Jossv4_computers20000195000--0.0022.132%
2015-04-26alpertronManual testing500000150000001222167.9240.0848.747%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1998-11-07ANONYMOUSv4_computers212570.012
2003-07-21ANONYMOUSv4_computers212580.024


ECM factoring results:
Total ECM effort:31.372 GHz-days
Estimated T-Level:25.716
DigitsB1CompleteFacMiss
201100014.5770.000%
25500001.66718.874%
302500000.14386.662%
3510000000.01099.007%


ECM Summary

B1B2factorcurvesGHz-days
10.085
50000500000024913.97
250000400000005017.31


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-11-14ANONYMOUSv4_computers8674760A8AD7857A0.072


PRP results:
dateuseridcompidcofactorsres64
2017-09-30alpertronManual testing
280088719453506332263
97708193218998523081
5E883BEB3284AF3D
2017-10-18Oliver KruseThreadripper-PC
97708193218998523081
280088719453506332263
5E883BEB3284AF3D


CERT results:
No CERT results for M1616623


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
B1 = 20000, B2 = 195000 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
103
104
105
106
103
104
105
106
107
108
TF factor-bounds graph:
258
257
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.72 ~= 69-bit
250
260
270
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Last modified: 2024-02-09T03:30:02+00:00