is 2 2556493 - 1
has 769582 decimal digits
takes 0.177 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L3924516181D5C258double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26711.622967.1642%2000000600000000.51907.6647%12.141969.6809%2.5168%
PrimeNet2590.030062.7119%110002000000.00212.6865%0.032263.7136%1.0018%
GPU722630.624365.0794%120001800000.00211.4788%0.626465.5958%0.5164%
Difference+4+10.9986+2.0848%+1988000+59820000+0.5168+6.1859%+11.5155+4.0852%+4.0852%

Known prime factors (2 factors, 156.7 bits, 0.00613018% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2556493545770541118690506812065.56510674203706380
22 × 5 × 139 × 3839641621
2010-05-0713938396416214.840421.03939.296
255649327520769216470399601102066392891.153538252387479066040883
21803 × 37549 × 126079 × 5214691
2018-12-261260795214691242,994,7600.04060.0534

1 Composite Factors:
exponentprime factorscomposite factordigitsbits*
255649315020025107275650146883577297906243084367367115948156.718
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-23T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.293%
2003-11-08T00:00:00Team Prime Ribv4_computers15000198750---0.003--0.885%
2018-12-27T01:29:06alpertronlaptop2200000060000000122891.1530.5190.3551.0387.665%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.030--
2022-03-11T02:04:59LordJuliusManual testing21260--0.060--
2009-02-01T10:29:00Sturle Sundekorsmo.ifi260261--0.060--


ECM factoring results:

Old Calculation Method

Total ECM effort:0.277 GHz-days
Estimated T-Level:0.150
DigitsB1CurvesCompleteFacMiss
20110003 / 1000.03097.030%
25500003 / 2800.01198.932%

New Calculation Method

Total ECM effort:0.277 GHz-days
Estimated T-Level:0.150
DigitsB1CompleteFacMiss
20110000.09790.776%
25500000.00999.129%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
50000500000030.277


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-26T00:00:00Smegheadsv4_computersBF564044A3D03B__0.177
1999-09-22T00:00:00Kevin Jagetv4_computers3924516181D5C2580.177


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-14T23:12:43Oliver KruseGTX-00F2F0DA29D86AB__no
2017-12-01T15:09:14kkmrkkblmbrbkc4.xlarge
54577054111869050681
0F2F0DA29D86AB__no
2018-12-27T02:01:24ATHec2-PRPCF
54577054111869050681
2752076921647039960110206639
0F2F0DA29D86ABCEno


P-1 factor-bounds graph:
B1 = 2000000, B2 = 60000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 15000, B2 = 198750 (P-1 stage 2)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
101
102
103
104
105
106
107
101
102
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
267
261
260
259
250
260
270
280
290
2100
Last modified: 2022-03-11T02:04:59+00:00