is 2 56531 - 1
has 17018 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Assigned as ECM on 2024-02-18, 0.0% done, ETC 2024-02-24
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual267525.621776.1194 %62000000077248347649473072,384.855830.8231 %72,910.477483.4801 %
Target2440.000063.6364 %500500000.00002.1129 %0.000064.4047 %
Difference+23+525.6216+12.4830 %+619999500+772483476444730+72,384.8557+28.7102%+72,910.4774+19.0755 %

Known prime factors (2 factors, 55.6 bits, 0.09843835% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
56531113063616.7871
1
-111.544e-131.720e-93.500e-9
565314994049165191238.8614417089
3 × 43 × 97 × 353
2008-08-26973536.478e-71.908e-73.395e-7

1 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-10-02kkmrkkblmbrbkManual testing100000000200000000012
skipped known factor: 113063
skipped known factor: 499404916519
---39.720%
2023-04-24JacobZGreatLakes620000000772483476494730
skipped known factor: 113063
skipped known factor: 499404916519
--113,57870.955%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-05-03ATHcolab-Pp215000000150000000027--0.176


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2008-08-26ANONYMOUSManual testing??38.86112


ECM factoring results:
Total ECM effort:118.399 GHz-days
Estimated T-Level:32.942
DigitsB1CompleteFacMiss
2011000177.3560.000%
255000033.9230.000%
302500004.9250.726%
3510000000.58855.524%
4030000000.05994.276%
45110000000.00599.496%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002810.327
250000250000005853.619
100000010000000043912.22
1000000218700000010.193
1000000218700000010.193
1000000413504091015082.28
214982044648301685019.77


Lucas-Lehmer results:
No L-L results for M56531


PRP results:
dateuseridcompidcofactorsres64
2017-09-21Oliver KruseOllaptop
113063
499404916519
D16CAF3BB5CF8479
2017-09-21Oliver KruseManual testing
113063
499404916519
D16CAF3BB5CF8479
2017-10-13kkmrkkblmbrbkManual testing
113063
499404916519
D16CAF3BB5CF8479
2020-04-17Oliver KruseAddPrpType5
113063
499404916519
7730265FF99C6F7F
2022-05-12Jorge CoveiroManual testing
113063
7730265FF99C6F7F


CERT results:
No CERT results for M56531


P-1 factor-bounds graph:
B1 = 620000000, B2 = 772483476494730 (P-1 stage 2)
B1 = 620000000 (P-1 stage 1)
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
100
101
102
103
104
105
106
107
108
109
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
TF factor-bounds graph:
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=32.94 ~= 93-bit
250
260
270
280
290
2100
JSON version of this page
Last modified: 2024-02-22T09:58:04+00:00