is 2 6918827 - 1
has 2082775 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-LA27A5D61A60B3542double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.221968.0556%1000000300000000.81574.5591%139.037769.5119%
Target2674.294665.6716%450009000000.02902.2362%4.323666.4393%
Difference+5+133.9273+2.3839%+955000+29100000+0.7868+2.3228%+134.7141+3.0726%

Known prime factors:
No known factors for M6918827

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-08-31ANONYMOUSv4_computers35000472500---0.019--0.884%
2012-08-15NesowaEPC850001508750---0.051--1.565%
2019-04-28takahashivaio30000050000006---0.176--2.682%
2021-05-24takahashivaio10000003000000012---0.816--4.559%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-06-29ANONYMOUSv4_computers21262--0.089--
1998-11-21ANONYMOUSv4_computers21262--0.089--
2004-03-16Sturle Sundev4_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--4.320--
2020-05-15TJAOIManual testing268269--8.640--
2021-07-18takahashiManual testing269270--17.28--
2021-08-10SRBaseManual testing270271--34.56--
2021-09-25SRBaseManual testing271272--69.12--


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)
1999-07-04ANONYMOUSv4_computersA27A5D61A60B35421.509
2001-09-10ANONYMOUSv4_computersA27A5D61A60B35421.509


PRP results:
No PRP results for M6918827


P-1 factor-bounds graph:
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 300000, B2 = 5000000 (P-1 stage 2)
B1 = 300000 (P-1 stage 1)
B1 = 85000, B2 = 1508750 (P-1 stage 2)
B1 = 85000 (P-1 stage 1)
B1 = 35000, B2 = 472500 (P-1 stage 2)
B1 = 35000 (P-1 stage 1)
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108
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