is 2 2543621 - 1
has 765707 decimal digits
takes 0.176 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L8F9A6B4B21814955double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26711.681767.1642%150001987500.00250.8838%11.684367.4544%0.2902%
PrimeNet2590.030262.7119%110002000000.00212.6840%0.032363.7127%1.0008%
GPU722630.627565.0794%120001800000.00211.4773%0.629665.5952%0.5159%
Difference+4+11.0543+2.0848%+3000+18750+0.0004-0.5935%+11.0547+1.8591%+1.8591%

Known prime factors (1 factor, 66.7 bits, 0.00262231% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
25436211200097123970048043832166.70223590328983171
2584207 × 9128653
2010-04-30258420791286538.97410.29580.5289

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-23T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.292%
2003-11-08T00:00:00Team Prime Ribv4_computers15000198750---0.003--0.884%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-15T00:00:00Brap_Onv4_computers21259--0.030--
2022-03-11T02:04:58LordJuliusManual testing21260--0.060--
2009-01-31T19:06:00Sturle Sundeaalto.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
20110000.11589.102%
25500000.01198.938%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
50000500000030.277


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-30T00:00:00ANONYMOUSv4_computers8F9A6B4B218149550.176


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-14T19:52:16Oliver KruseGTX-0F988AD365C71A8__no
2017-12-01T08:09:16storm5510HP-Z220-CMT
120009712397004804383
F988AD365C71A8__no


P-1 factor-bounds graph:
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)
102
103
104
105
106
107
102
103
104
105
106
107
TF factor-bounds graph:
267
261
260
259
250
260
270
280
290
2100
Last modified: 2022-03-11T02:04:58+00:00