is 2 6908813 - 1
has 2079760 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-L3486786D4826E942double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.422368.0556%40000004568186709.06528.0769%147.487470.6357%
Target2674.300965.6716%450009000000.02902.2357%4.329866.4391%
Difference+5+134.1214+2.3839%+3955000+455918670+9.0362+5.8412%+143.1576+4.1966%

Known prime factors:
No known factors for M6908813

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-08-31BJBv4_computers35000542500---0.020--0.921%
2012-08-11NesowaEPC850001487500---0.051--1.559%
2018-03-15Squeeky_Squirreli5-5250U_16004050001225125012---0.332--3.404%
2021-11-18Seth_TrManual testing30000007500000012---2.189--5.981%
2021-11-30Seth_TrManual testing4000000456818670---9.065--8.077%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-21ANONYMOUSv4_computers21262--0.089--
2005-07-01ANONYMOUSv4_computers21263--0.231--
2014-02-09NesowaManual testing263264--0.284--
2014-02-18lycornManual testing264265--0.541--
2015-06-21VictordeHollanderManual testing265266--1.082--
2016-04-01Gordon SpenceManual testing266267--2.163--
2018-05-23ramgeisManual testing267268--4.326--
2019-12-11mnd9Manual testing268269--8.653--
2020-12-21takahashiManual testing269270--17.31--
2021-08-10SRBaseManual testing270271--34.61--
2021-09-25SRBaseManual testing271272--69.22--


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)
1999-06-26ANONYMOUSv4_computers3486786D4826E9421.507
2001-08-31BJBv4_computers3486786D4826E9421.507


PRP results:
No PRP results for M6908813


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 = 405000, B2 = 12251250 (P-1 stage 2)
B1 = 405000 (P-1 stage 1)
B1 = 85000, B2 = 1487500 (P-1 stage 2)
B1 = 85000 (P-1 stage 1)
B1 = 35000, B2 = 542500 (P-1 stage 2)
B1 = 35000 (P-1 stage 1)
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109
TF factor-bounds graph:
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270
269
268
267
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265
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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