is 2 6915907 - 1
has 2081896 decimal digits
takes 1.508 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LFD15B2F5E05BEEECdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.280368.0556%40000004568186709.06528.0777%147.345470.6359%
Target2674.296565.6716%450009000000.02902.2361%4.325466.4392%
Difference+5+133.9838+2.3839%+3955000+455918670+9.0362+5.8416%+143.0200+4.1967%

Known prime factors:
No known factors for M6915907

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-08-26ANONYMOUSv4_computers3000030000---0.009--0.234%
2011-09-03Carsten Kossendeymother44000013310000---0.361--3.504%
2021-11-09Seth_TrManual testing30000007500000012---2.189--5.981%
2021-12-02Seth_TrManual testing4000000456818670---9.065--8.078%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05ANONYMOUSv4_computers21262--0.089--
2005-02-12ANONYMOUSv4_computers21263--0.231--
2014-02-09NesowaManual testing263264--0.284--
2014-02-17lycornManual testing264265--0.540--
2015-06-26VictordeHollanderManual testing265266--1.081--
2016-04-02Gordon SpenceManual testing266267--2.161--
2018-02-26-Anonymous-Manual testing267268--4.322--
2020-05-15TJAOIManual testing268269--8.644--
2021-07-18takahashiManual testing269270--17.29--
2021-08-11SRBaseManual testing270271--34.58--
2021-09-25SRBaseManual testing271272--69.15--


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)
1999-04-23ANONYMOUSv4_computersFD15B2F5E05BEEEC1.508
2001-09-22ANONYMOUSv4_computersFD15B2F5E05BEEEC1.508


PRP results:
No PRP results for M6915907


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 = 13310000 (P-1 stage 2)
B1 = 440000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
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107
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105
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109
TF factor-bounds graph:
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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