is 2 6986717 - 1
has 2103212 decimal digits
takes 1.523 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L6517B2620FC959B3double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272136.878868.0556%40000004567054809.06328.0853%145.942070.6383%
Target2674.252965.6716%450009000000.02902.2398%4.281966.4405%
Difference+5+132.6259+2.3839%+3955000+455805480+9.0342+5.8454%+141.6602+4.1978%

Known prime factors:
No known factors for M6986717

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-09-22lettpv4_computers35000288750---0.015--0.757%
2011-12-02James HeinrichQ66001350002835000---0.089--2.034%
2020-02-01takahashivaio6000001200000012---0.386--3.586%
2021-11-29Seth_TrManual testing4000000456705480---9.063--8.085%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-21Orionv4_computers21262--0.088--
2005-08-16ANONYMOUSv4_computers21263--0.228--
2014-02-09NesowaManual testing263264--0.281--
2014-02-14lycornManual testing264265--0.535--
2015-07-03VictordeHollanderManual testing265266--1.070--
2016-04-28Gordon SpenceManual testing266267--2.139--
2018-02-26-Anonymous-Manual testing267268--4.278--
2020-04-10TJAOIManual testing268269--8.557--
2021-08-12takahashiManual testing269270--17.11--
2021-09-07SRBaseManual testing270271--34.23--
2021-10-08SRBaseManual testing271272--68.45--


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)
1999-03-15ANONYMOUSv4_computers7F52FF8A0519E3__1.523
1999-05-30twmossv4_computers6517B2620FC959B31.523
2001-11-17lettpv4_computers6517B2620FC959B31.523


PRP results:
No PRP results for M6986717


P-1 factor-bounds graph:
B1 = 4000000, B2 = 456705480 (P-1 stage 2)
B1 = 4000000 (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 = 288750 (P-1 stage 2)
B1 = 35000 (P-1 stage 1)
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107
103
104
105
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107
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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: 67.8
ECM T-Level=1.15 ~= -13-bit
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Last modified: 2023-04-26T21:34:10+00:00