is 2 6938461 - 1
has 2088685 decimal digits
takes 1.513 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L53ED1C2F491D3199double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272137.830868.0556%20000002588493605.05696.9797%142.887870.2852%
Target2674.282565.6716%450009000000.02902.2373%4.311566.4397%
Difference+5+133.5483+2.3839%+1955000+257949360+5.0280+4.7424%+138.5763+3.8455%

Known prime factors:
No known factors for M6938461

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-01-22ANONYMOUSv4_computers30000157500---0.012--0.580%
2011-06-16Carsten Kossendeyleela44000013310000---0.361--3.506%
2021-06-02Dylan DelgadoManual testing6300001890000012---0.514--3.948%
2021-12-06Seth_TrManual testing2000000258849360---5.057--6.980%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05S00030v4_computers21262--0.089--
2005-03-06ANONYMOUSv4_computers21263--0.230--
2014-02-09NesowaManual testing263264--0.283--
2014-02-16lycornManual testing264265--0.539--
2015-06-26VictordeHollanderManual testing265266--1.077--
2016-04-05Gordon SpenceManual testing266267--2.154--
2018-02-27-Anonymous-Manual testing267268--4.308--
2020-04-24TJAOIManual testing268269--8.616--
2021-07-25takahashiManual testing269270--17.23--
2021-08-11SRBaseManual testing270271--34.46--
2021-09-25SRBaseManual testing271272--68.93--


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)
1999-07-04Rob Johnstonv4_computers53ED1C2F491D31991.513
2002-04-14ANONYMOUSv4_computers53ED1C2F491D31991.513


PRP results:
No PRP results for M6938461


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, B2 = 157500 (P-1 stage 2)
B1 = 30000 (P-1 stage 1)
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109
TF factor-bounds graph:
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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