is 2 6942547 - 1
has 2089915 decimal digits
takes 1.514 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LDE056EC3A8826765double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272137.749768.0556%20000002588493605.05696.9801%142.806670.2853%
Target2674.280065.6716%450009000000.02902.2375%4.308966.4397%
Difference+5+133.4697+2.3839%+1955000+257949360+5.0280+4.7427%+138.4977+3.8456%

Known prime factors:
No known factors for M6942547

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-09-16Uwe Falckv4_computers35000341250---0.016--0.799%
2011-11-28James HeinrichQ66001300002827500---0.088--2.015%
2020-01-18takahashivaio6000001200000012---0.386--3.583%
2021-12-06Seth_TrManual testing2000000258849360---5.057--6.980%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-21ANONYMOUSv4_computers21262--0.088--
2005-03-06ANONYMOUSv4_computers21263--0.230--
2014-02-09NesowaManual testing263264--0.283--
2014-02-16lycornManual testing264265--0.538--
2015-06-26VictordeHollanderManual testing265266--1.076--
2016-04-05Gordon SpenceManual testing266267--2.153--
2018-05-23ramgeisManual testing267268--4.305--
2020-04-24TJAOIManual testing268269--8.611--
2021-07-28takahashiManual testing269270--17.22--
2021-08-13SRBaseManual testing270271--34.44--
2021-10-10SRBaseManual testing271272--68.89--


ECM factoring results:
Total ECM effort:1.989 GHz-days
Estimated T-Level:1.154
DigitsB1CompleteFacMiss
20110000.23179.392%
25500000.02197.887%
302500000.00199.865%


ECM Summary

B1B2factorcurvesGHz-days
50000500000061.989


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-23Phantomasv4_computersDE056EC3A88267651.514
2001-09-22Uwe Falckv4_computersDE056EC3A88267651.514


PRP results:
No PRP results for M6942547


P-1 factor-bounds graph:
B1 = 2000000, B2 = 258849360 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 600000, B2 = 12000000 (P-1 stage 2)
B1 = 600000 (P-1 stage 1)
B1 = 130000, B2 = 2827500 (P-1 stage 2)
B1 = 130000 (P-1 stage 1)
B1 = 35000, B2 = 341250 (P-1 stage 2)
B1 = 35000 (P-1 stage 1)
103
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105
106
107
103
104
105
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107
108
109
TF factor-bounds graph:
272
271
270
269
268
267
266
265
264
263
262
this exponent TF target: 67
TF double-checked to: 67.7
ECM T-Level=1.15 ~= -13-bit
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Last modified: 2023-03-23T17:39:31+00:00