is 2 1868387 - 1
has 562441 decimal digits
takes 0.101 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
-unknown- primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26715.903568.6567%50000005150000002.579010.8017%18.482672.0423%3.3856%
PrimeNet2570.010363.1579%90001600000.00143.0286%0.011664.2737%1.1158%
GPU722610.164465.5738%100001500000.00141.6893%0.165866.1553%0.5816%
Difference+6+15.7391+3.0829%+4990000+514850000+2.5777+9.1124%+18.3168+5.8870%+5.8870%

Known prime factors (2 factors, 136.1 bits, 0.00728345% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1868387479217104266670811755.41212824353420
22 × 5 × 31 × 67 × 308723
-673087230.00280.00130.0025
186838719254878089640582194008232580.671515280776671015753
10429 × 49408454949757
2021-03-281042949408454949757131,427211,752395,494

1 Composite Factors:
exponentprime factorscomposite factordigitsbits*
18683879227266921125326136502296795313671840766341136.083
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-03-16T12:37:45alpertronManual testing5000001500000012-
skipped known factor: 47921710426667081
--0.101--5.081%
2021-06-08T11:20:49happy5214Manual testing5000000515000000-
skipped known factor: 47921710426667081
--2.579--10.802%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-06-08T11:20:49happy5214Manual testing250000019500000027--1.107


Trial Factoring results:
No TF results for M1868387


ECM factoring results:

Old Calculation Method

Total ECM effort:15.664 GHz-days
Estimated T-Level:23.661
DigitsB1CurvesCompleteFacMiss
2011000205 / 1002.05012.741%
2550000205 / 2800.73248.025%

New Calculation Method

Total ECM effort:15.664 GHz-days
Estimated T-Level:23.661
DigitsB1CompleteFacMiss
20110006.9840.093%
25500000.63253.130%
302500000.03996.164%
3510000000.00299.820%


ECM Summary

B1B2factorcurvesGHz-days
50000485000070.479
500005000000261.800
50000500000050.346
50000660000016713.04


Lucas-Lehmer results:
No L-L results for M1868387


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-04T10:44:04Oliver KruseGTX-0
47921710426667081
84B79B042A8D68__no
2017-11-07T13:39:47kkmrkkblmbrbkc4.xlarge
47921710426667081
84B79B042A8D68__no
2021-03-30T11:08:23Oliver KruseThreadripper-PC
47921710426667081
1925487808964058219400823
672B2513AD773A3Fno


P-1 factor-bounds graph:
B1 = 5000000, B2 = 515000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2021-09-10T07:33:42+00:00