is 2 6912943 - 1
has 2081004 decimal digits
takes 1.507 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LEEDF5FD87765B8FBdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.339668.0556%40000004568186709.06528.0774%147.404770.6358%
Target2674.298365.6716%450009000000.02902.2359%4.327366.4392%
Difference+5+134.0413+2.3839%+3955000+455918670+9.0362+5.8414%+143.0775+4.1966%

Known prime factors:
No known factors for M6912943

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-08-31ANONYMOUSv4_computers3000030000---0.009--0.234%
2011-09-03Carsten Kossendeymother44000013420000---0.363--3.510%
2021-11-19Seth_TrManual testing30000007500000012---2.189--5.981%
2021-12-01Seth_TrManual testing4000000456818670---9.065--8.077%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05ANONYMOUSv4_computers21261--0.044--
1998-07-05ANONYMOUSv4_computers21262--0.089--
2005-02-02ANONYMOUSv4_computers21263--0.231--
2014-02-09NesowaManual testing263264--0.284--
2014-02-17lycornManual testing264265--0.540--
2015-06-26VictordeHollanderManual testing265266--1.081--
2016-04-01Gordon SpenceManual testing266267--2.162--
2018-02-26-Anonymous-Manual testing267268--4.324--
2020-02-23mnd9Manual testing268269--8.648--
2021-07-18takahashiManual testing269270--17.30--
2021-08-10SRBaseManual testing270271--34.59--
2021-09-25SRBaseManual testing271272--69.18--


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)
1999-08-31ANONYMOUSv4_computersEEDF5FD87765B8FB1.507
2002-01-08ANONYMOUSv4_computersEEDF5FD87765B8FB1.507


PRP results:
No PRP results for M6912943


P-1 factor-bounds graph:
B1 = 4000000, B2 = 456818670 (P-1 stage 2)
B1 = 3000000, B2 = 75000000 (P-1 stage 2)
B1 = 4000000 (P-1 stage 1)
B1 = 3000000 (P-1 stage 1)
B1 = 440000, B2 = 13420000 (P-1 stage 2)
B1 = 440000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
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105
106
107
103
104
105
106
107
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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: 2023-03-25T13:08:14+00:00