is 2 6961979 - 1
has 2095765 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-LE1FA3F6FDBBFC0D7double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272137.365268.0556%40000004568186709.06528.0828%146.430470.6376%
Target2674.268065.6716%450009000000.02902.2385%4.297066.4401%
Difference+5+133.0972+2.3839%+3955000+455918670+9.0362+5.8443%+142.1334+4.1975%

Known prime factors:
No known factors for M6961979

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-09-16ANONYMOUSv4_computers3000030000---0.009--0.234%
2011-09-05Carsten Kossendeymother44000013530000---0.365--3.519%
2021-11-07Seth_TrManual testing20000005800000012---1.597--5.522%
2021-12-05Seth_TrManual testing4000000456818670---9.065--8.083%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-11ANONYMOUSv4_computers21261--0.044--
1998-07-29garyfuv4_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--8.587--
2021-08-02takahashiManual testing269270--17.17--
2021-08-13SRBaseManual testing270271--34.35--
2021-09-25SRBaseManual testing271272--68.70--


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)
1999-06-06ANONYMOUSv4_computersE1FA3F6FDBBFC0D71.518
2001-12-22ANONYMOUSv4_computersE1FA3F6FDBBFC0D71.518


PRP results:
No PRP results for M6961979


P-1 factor-bounds graph:
B1 = 4000000, B2 = 456818670 (P-1 stage 2)
B1 = 2000000, B2 = 58000000 (P-1 stage 2)
B1 = 4000000 (P-1 stage 1)
B1 = 2000000 (P-1 stage 1)
B1 = 440000, B2 = 13530000 (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
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: 67.8
ECM T-Level=1.15 ~= -13-bit
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Last modified: 2023-04-26T21:34:10+00:00