is 2 6928661 - 1
has 2085735 decimal digits
takes 1.511 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L289B04428AFC90CEdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.025868.0556%20000002588493605.05696.9787%143.082770.2849%
Target2674.288665.6716%450009000000.02902.2367%4.317566.4395%
Difference+5+133.7372+2.3839%+1955000+257949360+5.0280+4.7420%+138.7652+3.8454%

Known prime factors:
No known factors for M6928661

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-08-31ANONYMOUSv4_computers3000030000---0.009--0.234%
2011-09-04Carsten Kossendeymother44000013310000---0.361--3.505%
2021-06-02Dylan DelgadoManual testing6300001890000012---0.514--3.947%
2021-12-07Seth_TrManual testing2000000258849360---5.057--6.979%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05ANONYMOUSv4_computers21261--0.044--
1998-07-21ANONYMOUSv4_computers21262--0.089--
1998-08-02ANONYMOUSv4_computers21262--0.089--
2005-02-18ANONYMOUSv4_computers21263--0.230--
2014-02-09NesowaManual testing263264--0.283--
2014-02-17lycornManual testing264265--0.539--
2015-06-26VictordeHollanderManual testing265266--1.079--
2016-04-03Gordon SpenceManual testing266267--2.157--
2018-02-25-Anonymous-Manual testing267268--4.314--
2020-05-01TJAOIManual testing268269--8.628--
2021-07-22takahashiManual testing269270--17.26--
2021-08-10SRBaseManual testing270271--34.51--
2021-09-25SRBaseManual testing271272--69.03--


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)
2000-01-04ANONYMOUSv4_computers289B04428AFC90CE1.511
2001-11-10ANONYMOUSv4_computers289B04428AFC90CE1.511


PRP results:
No PRP results for M6928661


P-1 factor-bounds graph:
B1 = 2000000, B2 = 258849360 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 630000, B2 = 18900000 (P-1 stage 2)
B1 = 440000, B2 = 13310000 (P-1 stage 2)
B1 = 630000 (P-1 stage 1)
B1 = 440000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
103
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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
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280
Last modified: 2023-04-26T21:34:10+00:00