is 2 2567197 - 1
has 772804 decimal digits
takes 0.178 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LA28B89D8D7AED2D7double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26711.574567.1642%17500041125000.03923.5398%11.613668.3265%1.1623%
PrimeNet2590.029962.7119%110002000000.00212.6886%0.032163.7144%1.0025%
GPU722630.621765.0794%120001800000.00211.4800%0.623865.5962%0.5168%
Difference+4+10.9528+2.0848%+163000+3932500+0.0370+2.0598%+10.9898+2.7303%+2.7303%

Known prime factors (1 factor, 69.9 bits, 0.00272159% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
256719710778807444272191043192269.869209933391248747
97 × 2164261765451
2015-08-1497216426176545189.31811,85922,150

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%
2010-12-21T01:09:00Jocelyn LaroucheManual testing2000020000---0.002--0.316%
2011-01-03T22:20:00Jocelyn LaroucheManual testing3000030000---0.003--0.433%
2011-01-10T23:57:00Jocelyn LaroucheManual testing5000050000---0.005--0.621%
2011-04-15T03:35:00James HeinrichWHS1750004112500---0.039--3.540%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.030--
1999-04-02T00:00:00ANONYMOUSv4_computers21259--0.030--
1999-04-13T00:00:00ANONYMOUSv4_computers21259--0.030--
1999-04-23T00:00:00ANONYMOUSv4_computers21259--0.030--
1999-05-09T00:00:00ANONYMOUSv4_computers21259--0.030--
1999-05-16T00:00:00ANONYMOUSv4_computers21259--0.030--
1999-05-23T00:00:00ANONYMOUSv4_computers21259--0.030--
2022-03-11T02:05:01LordJuliusManual testing21260--0.060--
2009-01-27T04:25:00Sturle Sundedittersdorf.ifi260261--0.060--
2012-06-17T15:42:00Sebastian HornbostelManual testing261262--0.120--
2013-01-23T08:30:00dbaughManual testing262263--0.382--
2015-02-23T17:24:00VictordeHollanderManual testing263264--0.765--
2015-02-23T17:24:00VictordeHollanderManual testing264265--1.455--


ECM factoring results:

Old Calculation Method

Total ECM effort:1.384 GHz-days
Estimated T-Level:0.750
DigitsB1CurvesCompleteFacMiss
201100015 / 1000.15086.006%
255000015 / 2800.05494.775%

New Calculation Method

Total ECM effort:1.384 GHz-days
Estimated T-Level:0.750
DigitsB1CompleteFacMiss
20110000.48461.639%
25500000.04495.721%
302500000.00399.731%


ECM Summary

B1B2factorcurvesGHz-days
500005000000121.108
50000500000030.277


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-13T00:00:00ANONYMOUSv4_computersA28B89D8D7AED2D70.178
1999-04-23T00:00:00ANONYMOUSv4_computersA28B89D8D7AED2D70.178
1999-05-09T00:00:00ANONYMOUSv4_computersA28B89D8D7AED2D70.178
1999-05-16T00:00:00ANONYMOUSv4_computersA28B89D8D7AED2D70.178
1999-05-23T00:00:00ANONYMOUSv4_computersA28B89D8D7AED2D70.178


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-15T03:20:52Oliver KruseGTX-3
1077880744427219104319
C6C2FDC76A9432__no
2017-12-01T20:13:38kkmrkkblmbrbkc4.xlarge
1077880744427219104319
C6C2FDC76A9432__no


P-1 factor-bounds graph:
B1 = 175000, B2 = 4112500 (P-1 stage 2)
B1 = 175000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000, B2 = 198750 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-03-11T02:05:01+00:00