is 2 2778547 - 1
has 836426 decimal digits
takes 0.215 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L74998A97AD6E9ED5double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26821.451867.6471%2700000840000000.79847.6846%22.250370.1333%2.4862%
PrimeNet2590.027662.7119%120002200000.00262.8578%0.030363.7775%1.0656%
GPU722630.574465.0794%150002400000.00311.7473%0.577565.6895%0.6102%
Difference+5+20.8774+2.5677%+2685000+83760000+0.7954+5.9373%+21.6728+4.4437%+4.4437%

Known prime factors (1 factor, 76.1 bits, 0.00273836% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2778547802409698891138849657992376.08714439376028030817
3 × 17 × 19 × 51599 × 288790807
2020-08-23515992887908077,364.21.76763.2911

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-17T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.242%
2010-11-10T22:07:00Jocelyn LaroucheManual testing1500015000---0.002--0.210%
2010-11-27T13:06:00markrtiny1100002392500---0.026--2.614%
2016-08-06T20:01:40Jocelyn LaroucheManual testing15200047850006---0.045--3.235%
2016-12-18T19:43:08Jocelyn Larouchelow 4M182400182400---0.020--1.171%
2017-01-10T10:25:03Jocelyn Larouchelow 4M218880218880---0.025--1.286%
2017-01-10T10:25:06Jocelyn Larouchelow 4M262656262656---0.029--1.407%
2017-03-11T20:25:00Jocelyn Larouchelow 4M31518731518706---0.053--3.284%
2017-03-25T02:44:51mikrMSI27000008400000012---0.798--7.685%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:21Mark RoseManual testing21260--0.055--
2009-01-28T02:02:00Sturle Sundeghini.ifi260261--0.055--
2012-03-29T08:04:00Grant McCrackenthumper261262--0.111--
2013-01-14T12:31:00dbaughManual testing262263--0.353--
2015-04-21T09:20:00VictordeHollanderManual testing263264--0.707--
2015-04-21T09:20:00VictordeHollanderManual testing264265--1.345--
2015-12-10T13:38:51omylistManual testing265266--2.689--
2017-10-14T11:30:24Gordon SpenceManual testing266267--5.379--
2019-02-24T11:40:39chuenkitManual testing267268--10.76--


ECM factoring results:

Old Calculation Method

Total ECM effort:3.850 GHz-days
Estimated T-Level:1.850
DigitsB1CurvesCompleteFacMiss
201100037 / 1000.37068.945%
255000037 / 2800.13287.601%

New Calculation Method

Total ECM effort:3.850 GHz-days
Estimated T-Level:1.850
DigitsB1CompleteFacMiss
20110001.19430.314%
25500000.10889.774%
302500000.00799.338%


ECM Summary

B1B2factorcurvesGHz-days
500005000000333.434
50000500000040.416


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-02T00:00:00ANONYMOUSv4_computers74998A97AD6E9ED50.215
2018-08-25T02:07:48kkmrkkblmbrbkold74998A97AD6E9ED50.215


PRP results:
dateuseridcompidcofactorsres64PRP
2020-08-23T18:49:04mrh.orgw
80240969889113884965799
5300E0497637376Bno
2020-08-24T08:32:34kutensdeneb
80240969889113884965799
5300E0497637376Bno


P-1 factor-bounds graph:
B1 = 2700000, B2 = 84000000 (P-1 stage 2)
B1 = 2700000 (P-1 stage 1)
B1 = 315187, B2 = 3151870 (P-1 stage 2)
B1 = 152000, B2 = 4785000 (P-1 stage 2)
B1 = 315187 (P-1 stage 1)
B1 = 262656 (P-1 stage 1)
B1 = 110000, B2 = 2392500 (P-1 stage 2)
B1 = 218880 (P-1 stage 1)
B1 = 182400 (P-1 stage 1)
B1 = 152000 (P-1 stage 1)
B1 = 110000 (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: 2020-08-24T08:32:34+00:00