is 2 256181 - 1
has 77119 decimal digits
takes 0.002 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
Actualunknown30000000100358126969105,417.947373.0257%5,417.947373.0257%73.0257%
PrimeNet2400.000055.0000%2600700000.000114.2551%0.000161.4148%6.4148%
GPU722440.000059.0909%45001100000.000110.1985%0.000163.2630%4.1721%
Difference-440.0000-59.0909%+29995500+10035812586910+5,417.9472+62.8272%+5,417.9472+9.7627%+9.7627%

Known prime factors (2 factors, 110.5 bits, 0.04313856% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
25618119982119824.25239
3 × 13
-3138.798e-123.512e-86.050e-8
256181926885734028197603482041292686.261180904464817491852144
24 × 32 × 19 × 61 × 1083935293940489
2020-11-22611083935293940489119,486,808585,1441,092,887

1 Composite Factors:
exponentprime factorscomposite factordigitsbits*
256181185211410367537938682929634196935134110.513
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2021-09-05T19:58:20Oliver KruseOllaptop30000000300000000024-
skipped known factor: 19982119
--1.901--44.068%
2022-04-27T10:45:29Oliver KruseThreadripper-PC3000000010035812696910-
skipped known factor: 19982119
--5,418--63.170%


Trial Factoring results:
No TF results for M256181


ECM factoring results:

Old Calculation Method

Total ECM effort:11.362 GHz-days
Estimated T-Level:26.945
DigitsB1CurvesCompleteFacMiss
2011000530 / 1005.3000.486%
2550000530 / 2801.89315.013%
30250000249 / 6400.38967.749%

New Calculation Method

Total ECM effort:11.362 GHz-days
Estimated T-Level:26.945
DigitsB1CompleteFacMiss
201100029.8150.000%
25500003.8572.114%
302500000.37968.478%
3510000000.03097.081%
4030000000.00299.809%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002812.048
250000250000002067.505
2500002500000010.036
2500003300000070.282
2500003475000070.288
2500003825000070.300
25000038500000210.902


Lucas-Lehmer results:
No L-L results for M256181


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-22T07:48:36Oliver KruseOllaptop
19982119
E7EEE24A12975F__no
2017-09-22T10:06:36Oliver KruseManual testing
19982119
E7EEE24A12975F__no
2017-10-12T17:07:57Oliver KruseGTX-0E7EEE24A12975F__no
2017-11-06T16:19:44kkmrkkblmbrbkc4.xlarge
19982119
E7EEE24A12975F__no
2020-04-17T20:17:17Oliver KruseAddPrpType5
19982119
7A00AB15E6FB02__no
2020-11-22T15:28:34mrhx
19982119
92688573402819760348204129
7A00AB15E6FB02A0no


P-1 factor-bounds graph:
B1 = 30000000, B2 = 10035812696910 (P-1 stage 2)
B1 = 30000000, B2 = 3000000000 (P-1 stage 2)
B1 = 30000000 (P-1 stage 1)
100
101
102
103
104
105
106
107
108
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
1016
TF factor-bounds graph:
220
230
240
250
260
270
280
290
2100
Last modified: 2022-05-17T02:49:58+00:00