is 2 6918287 - 1
has 2082612 decimal digits
takes 1.509 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L8E9F2BCF4682FAB4double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.232768.0556%40000004143239108.33317.9711%146.565870.6019%
Target2674.295065.6716%450009000000.02902.2362%4.323966.4393%
Difference+5+133.9377+2.3839%+3955000+413423910+8.3042+5.7349%+142.2419+4.1626%

Known prime factors:
No known factors for M6918287

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-12-22ANONYMOUSv4_computers35000341250---0.016--0.798%
2011-11-21James Heinrichi7-9201300002665000---0.085--1.986%
2020-01-11takahashivaio6000001200000012---0.386--3.581%
2021-11-25Seth_TrManual testing400000011000000012---3.091--6.531%
2021-12-02Seth_TrManual testing4000000414323910---8.333--7.971%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05ANONYMOUSv4_computers21262--0.089--
1999-11-24ANONYMOUSv4_computers21263--0.231--
2001-12-22ANONYMOUSv4_computers21263--0.231--
2014-02-09NesowaManual testing263264--0.284--
2014-02-17lycornManual testing264265--0.540--
2015-06-26VictordeHollanderManual testing265266--1.080--
2016-04-02Gordon SpenceManual testing266267--2.160--
2018-02-27-Anonymous-Manual testing267268--4.321--
2020-05-15TJAOIManual testing268269--8.641--
2021-07-18takahashiManual testing269270--17.28--
2021-08-10SRBaseManual testing270271--34.56--
2021-09-25SRBaseManual testing271272--69.13--


ECM factoring results:
Total ECM effort:2.984 GHz-days
Estimated T-Level:1.731
DigitsB1CompleteFacMiss
20110000.34670.740%
25500000.03296.848%
302500000.00299.798%


ECM Summary

B1B2factorcurvesGHz-days
50000500000092.984


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-12-23ebravickv4_computers8E9F2BCF4682FAB41.509
2002-01-22ANONYMOUSv4_computers8E9F2BCF4682FAB41.509


PRP results:
No PRP results for M6918287


P-1 factor-bounds graph:
B1 = 4000000, B2 = 414323910 (P-1 stage 2)
B1 = 4000000, B2 = 110000000 (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 = 130000, B2 = 2665000 (P-1 stage 2)
B1 = 130000 (P-1 stage 1)
B1 = 35000, B2 = 341250 (P-1 stage 2)
B1 = 35000 (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
this exponent TF target: 67
TF double-checked to: 67.8
ECM T-Level=1.73 ~= -11-bit
250
260
270
280
Last modified: 2023-03-25T13:08:14+00:00