is 2 6962561 - 1
has 2095940 decimal digits
takes 1.518 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LDA61C82CBE86948Cdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272137.353768.0556%20000002588493605.05696.9822%142.410770.2860%
Target2674.267765.6716%450009000000.02902.2386%4.296666.4401%
Difference+5+133.0860+2.3839%+1955000+257949360+5.0280+4.7437%+138.1140+3.8459%

Known prime factors:
No known factors for M6962561

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-09-16ANONYMOUSv4_computers35000341250---0.016--0.799%
2011-12-10James HeinrichQ66001350002835000---0.089--2.033%
2020-01-25takahashivaio6000001200000012---0.386--3.584%
2021-12-07Seth_TrManual testing2000000258849360---5.057--6.982%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05ANONYMOUSv4_computers21261--0.044--
1998-07-21ANONYMOUSv4_computers21262--0.088--
2005-07-17ANONYMOUSv4_computers21263--0.229--
2014-02-09NesowaManual testing263264--0.282--
2014-02-15lycornManual testing264265--0.537--
2015-06-26VictordeHollanderManual testing265266--1.073--
2016-04-25Gordon SpenceManual testing266267--2.147--
2018-02-26-Anonymous-Manual testing267268--4.293--
2020-04-24TJAOIManual testing268269--8.586--
2021-08-04takahashiManual testing269270--17.17--
2021-09-07SRBaseManual testing270271--34.34--
2021-09-28SRBaseManual testing271272--68.69--


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)
1999-07-27ANONYMOUSv4_computersDA61C82CBE86948C1.518
2001-09-30ANONYMOUSv4_computersDA61C82CBE86948C1.518


PRP results:
No PRP results for M6962561


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 = 135000, B2 = 2835000 (P-1 stage 2)
B1 = 135000 (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
106
107
108
109
TF factor-bounds graph:
272
271
270
269
268
267
266
265
264
263
262
261
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