is 2 2478257 - 1
has 746030 decimal digits
takes 0.172 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LA8D3950EED4584B9double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26824.051167.6471%2382500857701000.69657.5473%24.747770.0888%2.4418%
PrimeNet2590.031062.7119%100001800000.00192.5337%0.032963.6566%0.9448%
GPU722630.644065.0794%110001600000.00191.3796%0.645965.5611%0.4818%
Difference+5+23.4071+2.5677%+2371500+85610100+0.6946+6.1676%+24.1017+4.5277%+4.5277%

Known prime factors (1 factor, 85.3 bits, 0.00344004% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2478257461003016075638616017681292685.2539300952566171277152
25 × 3 × 71 × 556067 × 2453978341
2020-05-2455606724539783413,416,37913.50025.115

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-14T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.234%
2003-10-31T00:00:00Team Prime Ribv4_computers15000228750---0.003--0.785%
2010-11-20T12:24:00Jocelyn LaroucheManual testing2000020000---0.002--0.263%
2011-01-21T00:06:00Oscar Östlin950001947500---0.020--2.378%
2014-09-02T00:10:00Jocelyn LaroucheManual testing120899120899---0.012--0.917%
2014-10-25T09:15:00mikrMSI238250085770100---0.697--7.547%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-05-02T00:00:00Stephen Woodv4_computers21259--0.031--
2016-02-23T16:29:15Mark RoseManual testing259260--0.031--
2009-01-14T23:40:00Sturle Sundehindemith.ifi260261--0.062--
2012-06-08T23:44:00Sebastian HornbostelManual testing261262--0.124--
2013-08-21T01:30:00David CampeauManual testing262263--0.396--
2015-03-03T21:37:00VictordeHollanderManual testing263264--0.792--
2015-03-03T21:37:00VictordeHollanderManual testing264265--1.508--
2015-10-28T09:42:40ramgeisManual testing265266--3.015--
2017-07-22T20:28:36Gordon SpenceManual testing266267--6.031--
2019-05-27T13:36:57TJAOIManual testing267268--12.06--


ECM factoring results:

Old Calculation Method

Total ECM effort:3.765 GHz-days
Estimated T-Level:2.050
DigitsB1CurvesCompleteFacMiss
201100041 / 1000.41066.228%
255000041 / 2800.14686.356%

New Calculation Method

Total ECM effort:3.765 GHz-days
Estimated T-Level:2.050
DigitsB1CompleteFacMiss
20110001.32326.645%
25500000.12088.733%
302500000.00799.267%


ECM Summary

B1B2factorcurvesGHz-days
500005000000393.581
50000500000020.184


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-16T00:00:00Stephen Woodv4_computersA8D3950EED4584B90.172
2018-05-30T00:47:10kkmrkkblmbrbkoldA8D3950EED4584B90.172


PRP results:
dateuseridcompidcofactorsres64PRP
2020-05-24T06:34:23CrypticCluecruncher
46100301607563861601768129
6118CDA70F91480Bno
2020-05-26T05:51:39Luigi Morelli9800X
46100301607563861601768129
6118CDA70F91480Bno


P-1 factor-bounds graph:
B1 = 2382500, B2 = 85770100 (P-1 stage 2)
B1 = 2382500 (P-1 stage 1)
B1 = 95000, B2 = 1947500 (P-1 stage 2)
B1 = 120899 (P-1 stage 1)
B1 = 95000 (P-1 stage 1)
B1 = 15000, B2 = 228750 (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)
102
103
104
105
106
107
102
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
259
250
260
270
280
290
2100
Last modified: 2020-05-26T05:51:39+00:00