is 2 1865681 - 1
has 561626 decimal digits
takes 0.101 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L79EA7727801CD8F7double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26715.926668.6567 %500000150000000.10155.0804 %16.028170.2491 %
Target2610.164665.5738 %100007500000.00401.6889 %0.168666.1552 %
Difference+6+15.7619+3.0829 %+490000+14250000+0.0975+3.3915%+15.8594+4.0939 %

Known prime factors (1 factor, 64.3 bits, 0.00344513% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1865681223239926707795919292064.2755982800026044
22 × 3 × 498566668837
2008-10-3044985666688371.90782,136.73,990.8

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-03-16alpertronManual testing5000001500000012---8.883%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2003-01-09ANONYMOUSv4_computers212580.021


ECM factoring results:
Total ECM effort:39.377 GHz-days
Estimated T-Level:25.710
DigitsB1CompleteFacMiss
201100014.9560.000%
25500001.67818.669%
302500000.14286.769%
3510000000.01099.031%


ECM Summary

B1B2factorcurvesGHz-days
10.103
500005000000372.561
50000660000021216.55
250000400000004720.16


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-29ANONYMOUSv4_computers79EA7727801CD8F70.101


PRP results:
dateuseridcompidcofactorsres64
2017-10-04Oliver KruseGTX-0
22323992670779591929
B2E693AB2D532B63
2017-11-07kkmrkkblmbrbkc4.xlarge
22323992670779591929
B2E693AB2D532B63


CERT results:
No CERT results for M1865681


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
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.71 ~= 69-bit
250
260
270
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Last modified: 2024-03-03T02:29:32+00:00