is 2 6908651 - 1
has 2079712 decimal digits
takes 1.506 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L27951CB50EC71B01double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.425568.0556%40000004568186709.06528.0769%147.490770.6357%
Target2674.301065.6716%450009000000.02902.2357%4.329966.4391%
Difference+5+134.1246+2.3839%+3955000+455918670+9.0362+5.8412%+143.1607+4.1966%

Known prime factors:
No known factors for M6908651

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-08-24ANONYMOUSv4_computers3000030000---0.009--0.234%
2002-04-07ANONYMOUSv4_computers3000030000---0.009--0.234%
2011-09-03Carsten Kossendeymother44000013420000---0.363--3.510%
2021-11-18Seth_TrManual testing30000007500000012---2.189--5.980%
2021-11-30Seth_TrManual testing4000000456818670---9.065--8.077%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-11ANONYMOUSv4_computers21261--0.044--
1998-08-02ANONYMOUSv4_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--4.327--
2019-12-11mnd9Manual testing268269--8.653--
2020-12-21takahashiManual testing269270--17.31--
2021-08-11SRBaseManual testing270271--34.61--
2021-09-25SRBaseManual testing271272--69.23--


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)
1999-06-15ANONYMOUSv4_computers27951CB50EC71B011.506
2000-01-19ANONYMOUSv4_computers27951CB50EC71B011.506
2000-02-23ANONYMOUSv4_computers27951CB50EC71B011.506
2000-05-05ANONYMOUSv4_computers27951CB50EC71B011.506
2002-05-05ANONYMOUSv4_computers27951CB50EC71B011.506


PRP results:
No PRP results for M6908651


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)
103
104
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
250
260
270
280
Last modified: 2023-04-26T21:34:10+00:00