is 2 6928643 - 1
has 2085730 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-LF74B2E1FA649DD4Bdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.026168.0556%720000216000000.58734.1202%138.613469.3717%
Target2674.288665.6716%450009000000.02902.2367%4.317566.4395%
Difference+5+133.7375+2.3839%+675000+20700000+0.5584+1.8834%+134.2959+2.9322%

Known prime factors:
No known factors for M6928643

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-12-01ANONYMOUSv4_computers30000232500---0.013--0.669%
2011-11-23James Heinrichi7-9201300002827500---0.088--2.015%
2020-01-14takahashivaio6000001200000012---0.386--3.582%
2021-06-02Dylan DelgadoManual testing7200002160000012---0.587--4.120%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05ANONYMOUSv4_computers21261--0.044--
1998-07-05ANONYMOUSv4_computers21262--0.089--
2004-03-16Sturle Sundev4_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)
1999-08-07ANONYMOUSv4_computersF74B2E1FA649DD4B1.511
2002-01-28ANONYMOUSv4_computersF74B2E1FA649DD4B1.511


PRP results:
No PRP results for M6928643


P-1 factor-bounds graph:
B1 = 720000, B2 = 21600000 (P-1 stage 2)
B1 = 600000, B2 = 12000000 (P-1 stage 2)
B1 = 720000 (P-1 stage 1)
B1 = 600000 (P-1 stage 1)
B1 = 130000, B2 = 2827500 (P-1 stage 2)
B1 = 130000 (P-1 stage 1)
B1 = 30000, B2 = 232500 (P-1 stage 2)
B1 = 30000 (P-1 stage 1)
103
104
105
106
103
104
105
106
107
108
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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270
280
Last modified: 2023-04-26T21:34:10+00:00