is 2 2681993 - 1
has 807361 decimal digits
takes 0.207 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LB84220FE4AE009F8double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26711.079067.1642 %2000000600000000.57797.7024 %11.656969.6933 %
Target2630.595165.0794 %1300011000000.00811.6225 %0.603265.6460 %
Difference+4+10.4840+2.0848 %+1987000+58900000+0.5698+6.0798%+11.0537+4.0474 %

Known prime factors (1 factor, 76.6 bits, 0.00285493% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
26819931120881956471890143327772476.56920896437024106516
22 × 15128857 × 345307597
2010-07-29151288573453075975,706.23.70903.9352

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2003-11-08ANONYMOUSv4_computers2048204800--0.0010.674%
2003-11-28Team Prime Ribv4_computers15000217500--0.0031.687%
2019-07-04alpertronManual testing20000006000000012---10.633%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2009-01-26Sturle Sundegaudi.ifi2602610.057


ECM factoring results:
Total ECM effort:0.323 GHz-days
Estimated T-Level:0.577
DigitsB1CompleteFacMiss
20110000.11589.102%
25500000.01198.938%


ECM Summary

B1B2factorcurvesGHz-days
10.081
50000500000030.243


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-06-20ANONYMOUSv4_computersB84220FE4AE009F80.207
1999-05-02ANONYMOUSv4_computersB84220FE4AE009F80.207


PRP results:
dateuseridcompidcofactorsres64
2017-10-19Oliver KruseGTX-2
112088195647189014332777
1010A6F6D35A6487
2017-12-03kkmrkkblmbrbkc4.xlarge
112088195647189014332777
1010A6F6D35A6487


CERT results:
No CERT results for M2681993


P-1 factor-bounds graph:
B1 = 2000000, B2 = 60000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 15000, B2 = 217500 (P-1 stage 2)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
102
103
104
105
106
107
108
102
103
104
105
106
107
108
109
TF factor-bounds graph:
261
this exponent TF target: 63
TF double-checked to: 67
ECM T-Level=0.58 ~= -15-bit
250
260
270
280
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Last modified: 2024-02-29T14:28:04+00:00