is 2 2784167 - 1
has 838118 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-L6E5B1A83B0D671BDdouble-checked
PRP9C2F03C0807C4782verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26821.408567.6471%3000000900000000.86687.8322%22.275370.1810%2.5340%
PrimeNet2590.027662.7119%120002200000.00262.8589%0.030263.7779%1.0660%
GPU722630.573265.0794%150002400000.00311.7480%0.576365.6898%0.6104%
Difference+5+20.8353+2.5677%+2985000+89760000+0.8638+6.0843%+21.6990+4.4913%+4.4913%

Known prime factors (1 factor, 68.7 bits, 0.00246867% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
27841674901934852716908800072168.73288032342397509
32 × 9781371377501
2021-02-039978137137750133.44159,683111,470

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-17T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.242%
2010-11-11T04:19:00Jocelyn LaroucheManual testing1500015000---0.002--0.211%
2010-11-25T15:18:00markrtiny1000002075000---0.023--2.483%
2014-10-28T23:25:00Jocelyn LaroucheManual testing123053123053---0.014--0.946%
2016-05-03T01:41:41Jocelyn LaroucheManual testing20000036000006---0.043--3.183%
2017-07-20T22:03:20Jocelyn Larouchelow 4M40000040000006---0.067--3.575%
2019-11-15T19:02:42BigBrotherWinston30000009000000012---0.867--7.832%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:21Mark RoseManual testing21260--0.055--
2009-01-28T18:26:00Sturle Sundegimba.ifi260261--0.055--
2012-03-08T08:43:00Grant McCrackenthumper261262--0.110--
2013-01-14T12:31:00dbaughManual testing262263--0.353--
2015-04-21T09:20:00VictordeHollanderManual testing263264--0.705--
2015-04-21T09:20:00VictordeHollanderManual testing264265--1.342--
2016-02-08T11:13:52ramgeisManual testing265266--2.684--
2017-10-19T22:32:30Gordon SpenceManual testing266267--5.368--
2019-02-25T02:38:33chuenkitManual testing267268--10.74--


ECM factoring results:

Old Calculation Method

Total ECM effort:7.702 GHz-days
Estimated T-Level:3.700
DigitsB1CurvesCompleteFacMiss
201100074 / 1000.74047.534%
255000074 / 2800.26476.739%

New Calculation Method

Total ECM effort:7.702 GHz-days
Estimated T-Level:3.700
DigitsB1CompleteFacMiss
20110002.3879.190%
25500000.21680.594%
302500000.01398.680%


ECM Summary

B1B2factorcurvesGHz-days
500005000000687.078
50000500000060.625


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-23T00:00:00ANONYMOUSv4_computers6E5B1A83B0D671BD0.215
2018-08-26T12:40:49kkmrkkblmbrbkold6E5B1A83B0D671BD0.215


PRP results:
dateuseridcompidcofactorsres64PRP
2021-02-03T20:57:13riccardo ubertiColab_noGPU12
490193485271690880007
9C2F03C0807C4782no


P-1 factor-bounds graph:
B1 = 3000000, B2 = 90000000 (P-1 stage 2)
B1 = 3000000 (P-1 stage 1)
B1 = 400000, B2 = 4000000 (P-1 stage 2)
B1 = 400000 (P-1 stage 1)
B1 = 200000, B2 = 3600000 (P-1 stage 2)
B1 = 100000, B2 = 2075000 (P-1 stage 2)
B1 = 200000 (P-1 stage 1)
B1 = 123053 (P-1 stage 1)
B1 = 100000 (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: 2021-02-03T20:57:13+00:00