is 2 2873491 - 1
has 865007 decimal digits
takes 0.222 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L1A28F6D55B5D5A9Fdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26820.743067.6471%50000002000000001.74989.1803%22.492870.6172%2.9701%
PrimeNet2590.026762.7119%130002400000.00282.9972%0.029663.8295%1.1176%
GPU722630.555465.0794%160002800000.00341.8700%0.558865.7324%0.6530%
Difference+5+20.1876+2.5677%+4984000+199720000+1.7464+7.3103%+21.9340+4.8848%+4.8848%

Known prime factors (1 factor, 73.5 bits, 0.00255873% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2873491135890165883281715968892373.5252364548312197284
22 × 3 × 31 × 6356312667197
2020-08-12316356312667197729.6738,78472,438

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.245%
2009-07-03T00:55:00Carsten Kossendeyleela15000161250---0.003--0.723%
2010-12-23T00:29:00Jocelyn LaroucheManual testing2000020000---0.002--0.272%
2011-01-03T22:20:00Jocelyn LaroucheManual testing3000030000---0.003--0.376%
2011-01-22T13:10:00Jocelyn LaroucheManual testing5000050000---0.006--0.544%
2011-02-06T11:32:00markrtiny2000005250000---0.053--3.470%
2017-08-19T15:19:08Jocelyn Larouchelow 4M40000040000006---0.067--3.590%
2019-10-21T02:06:05masserManual testing28800002880000012---0.481--6.428%
2020-03-01T15:03:12masserManual testing500000020000000012---1.750--9.180%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1997-12-30T00:00:00ANONYMOUSv4_computers21259--0.027--
2016-02-23T16:29:23Mark RoseManual testing259260--0.027--
2009-02-13T21:07:00Sturle Sundegorky.ifi260261--0.053--
2012-01-28T19:05:00Grant McCrackenthumper261262--0.107--
2013-01-07T13:47:00dbaughManual testing262263--0.342--
2015-04-21T09:21:00VictordeHollanderManual testing263264--0.683--
2015-04-21T09:21:00VictordeHollanderManual testing264265--1.300--
2016-02-18T12:13:59ramgeisManual testing265266--2.601--
2017-11-12T17:07:19Gordon SpenceManual testing266267--5.201--
2019-01-09T01:10:00chuenkitManual testing267268--10.40--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.406 GHz-days
Estimated T-Level:1.150
DigitsB1CurvesCompleteFacMiss
201100023 / 1000.23079.361%
255000023 / 2800.08292.100%

New Calculation Method

Total ECM effort:2.406 GHz-days
Estimated T-Level:1.150
DigitsB1CompleteFacMiss
20110000.74247.619%
25500000.06793.514%
302500000.00499.588%


ECM Summary

B1B2factorcurvesGHz-days
500005000000212.197
50000500000020.209


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-12-30T00:00:00ANONYMOUSv4_computers1A28F6D55B5D5A9F0.222
1999-09-22T00:00:00ANONYMOUSv4_computers1A28F6D55B5D5A9F0.222
2018-09-22T10:25:12kkmrkkblmbrbkold1A28F6D55B5D5A9F0.222


PRP results:
dateuseridcompidcofactorsres64PRP
2020-08-17T19:16:57atrenchDesktop
13589016588328171596889
8E6810E04EBA39C6no
2020-08-23T10:23:47oodairacom1
13589016588328171596889
8E6810E04EBA39C6no


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 2880000, B2 = 28800000 (P-1 stage 2)
B1 = 2880000 (P-1 stage 1)
B1 = 400000, B2 = 4000000 (P-1 stage 2)
B1 = 200000, B2 = 5250000 (P-1 stage 2)
B1 = 400000 (P-1 stage 1)
B1 = 200000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000, B2 = 161250 (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: 2020-08-23T10:23:47+00:00