is 2 2786573 - 1
has 838843 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-L-unknown--unknown-
PRP3AFC2ED40B6B8CC7verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26821.390067.6471%3000000900000000.86687.8329%22.256870.1812%2.5342%
PrimeNet2590.027662.7119%120002200000.00262.8593%0.030263.7780%1.0662%
GPU722630.572865.0794%150002400000.00311.7482%0.575865.6899%0.6105%
Difference+5+20.8173+2.5677%+2985000+89760000+0.8638+6.0847%+21.6810+4.4914%+4.4914%

Known prime factors (1 factor, 89.1 bits, 0.00319924% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
27865736863838683453692953331823832789.149123159139980429239667
32 × 1723 × 7942164182654881
2021-04-121723794216418265488168,042,16148,460,32890,510,398

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-17T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.242%
2010-11-11T11:52:00Jocelyn LaroucheManual testing1500015000---0.002--0.211%
2010-11-24T21:06:00markrtiny1000002075000---0.023--2.483%
2014-10-28T23:25:00Jocelyn LaroucheManual testing123033123033---0.014--0.946%
2016-05-04T08:48:51Jocelyn LaroucheManual testing20000036000006---0.043--3.183%
2017-07-20T22:03:20Jocelyn Larouchelow 4M40000040000006---0.067--3.575%
2019-11-15T10:48:49BigBrotherWinston30000009000000012---0.867--7.833%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:21Mark RoseManual testing21260--0.055--
2009-01-29T22:58:00Sturle Sundeinteravia.ifi260261--0.055--
2012-03-11T19:54:00Grant McCrackenthumper261262--0.110--
2013-01-10T10:21:00dbaughManual testing262263--0.352--
2015-04-21T09:20:00VictordeHollanderManual testing263264--0.705--
2015-04-21T09:20:00VictordeHollanderManual testing264265--1.341--
2016-02-08T11:13:53ramgeisManual testing265266--2.682--
2017-10-19T22:32:31Gordon SpenceManual testing266267--5.363--
2019-02-26T02:05:07chuenkitManual testing267268--10.73--


ECM factoring results:

Old Calculation Method

Total ECM effort:9.265 GHz-days
Estimated T-Level:4.450
DigitsB1CurvesCompleteFacMiss
201100089 / 1000.89040.882%
255000089 / 2800.31872.729%

New Calculation Method

Total ECM effort:9.265 GHz-days
Estimated T-Level:4.450
DigitsB1CompleteFacMiss
20110002.8715.664%
25500000.25977.146%
302500000.01698.415%


ECM Summary

B1B2factorcurvesGHz-days
500005000000828.536
50000500000070.729


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-02T00:00:00ANONYMOUSv4_computers5246F24915FA5F__0.215


PRP results:
dateuseridcompidcofactorsres64PRP
2021-04-13T06:16:48M89093871
686383868345369295333182383
3AFC2ED40B6B8CC7no


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 = 123033 (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: 2021-04-13T06:16:48+00:00