is 2 8243 - 1
has 2482 decimal digits
takes 0.000 GHz-days to do one PRP test
Has been fully factored.
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-
Cofactor is a certified prime

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actualunknown----0.00000.0000%
Target2440.000368.1818%500800000.00001.1907%0.000368.5607%
Difference-44-0.0003-68.1818%-500-800000.0000-1.1907%-0.0003-68.5607%

Known prime factors (4 factors, 8,243.0 bits, 100.00000000% known):
Remaining cofactor is a certified-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
824316487514.0091
1
-112.648e-131.474e-103.000e-10
824342072436871031.970255201
3 × 257 × 331
-2573314.298e-83.848e-87.710e-8
824322859179399649095457464888583410868119980742137.39213865813053287089322737406638002467621
3 × 7 × 11 × 193 × 1831 × 7333 × 12363585253 × 1873534067187773
2017-10-101236358525318735340671877731.986e+1315,04928,105
8243
click to show decimal representation
2,4278,059.6292017-10-10

4 Composite Factors:
P-1 results:
No P-1 results for M8243


Trial Factoring results:
No TF results for M8243


ECM factoring results:
Total ECM effort:22.112 GHz-days
Estimated T-Level:38.718
DigitsB1CompleteFacMiss
2011000939.9330.000%
2550000221.5610.000%
3025000040.6080.000%
3510000006.0320.240%
4030000000.74447.541%
45110000000.08092.351%
50440000000.00799.259%


ECM Summary

B1B2factorcurvesGHz-days
10000001000000002,4505.197
30000003000000002,65816.92


Lucas-Lehmer results:
No L-L results for M8243


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-21Oliver KruseOliver-PC
16487
4207243687
22A4518B19A1D3__no
2017-09-21Oliver KruseManual testing
16487
4207243687
22A4518B19A1D3__no
2017-10-10YarBerManual testing
16487
4207243687
228591793996490954574648885834108681199807
PRP
2017-10-12kkmrkkblmbrbkc4.xlargePRP
2017-11-09kkmrkkblmbrbkc4.large
16487
4207243687
228591793996490954574648885834108681199807
PRP


P-1 factor-bounds graph:
100
101
102
103
104
105
106
107
108
109
1010
1011
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
1016
TF factor-bounds graph:
this exponent TF target: 44
TF double-checked to: 67.9
ECM T-Level=38.72 ~= 112-bit
250
260
270
280
290
2100
2110
2120
2130
2140
Last modified: 2023-07-11T14:45:05+00:00