is 2 6988271 - 1
has 2103680 decimal digits
takes 1.524 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L5E7A1727D9F43A7Cdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272136.848468.0556%20000002416186504.76016.9165%141.608570.2650%
Target2674.252065.6716%450009000000.02902.2399%4.280966.4406%
Difference+5+132.5964+2.3839%+1955000+240718650+4.7312+4.6766%+137.3276+3.8244%

Known prime factors:
No known factors for M6988271

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-01-22ANONYMOUSv4_computers2500087500---0.009--0.432%
2011-06-09Carsten Kossendeyleela44500013572500---0.367--3.528%
2021-11-07Seth_TrManual testing20000005800000012---1.597--5.524%
2021-12-06Seth_TrManual testing2000000241618650---4.760--6.917%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-21ANONYMOUSv4_computers21262--0.088--
1999-12-01JCv4_computers21263--0.228--
2002-01-22ANONYMOUSv4_computers21263--0.228--
2014-02-09NesowaManual testing263264--0.281--
2014-02-14lycornManual testing264265--0.535--
2015-07-03VictordeHollanderManual testing265266--1.069--
2016-04-28Gordon SpenceManual testing266267--2.139--
2018-02-27-Anonymous-Manual testing267268--4.277--
2020-04-10TJAOIManual testing268269--8.555--
2021-08-13takahashiManual testing269270--17.11--
2021-09-06SRBaseManual testing270271--34.22--
2021-09-26SRBaseManual testing271272--68.44--


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)
1999-03-26ANONYMOUSv4_computers89085656F5090B__1.524
2000-01-19JCv4_computers5E7A1727D9F43A7C1.524
2002-11-02oerwinv4_computers5E7A1727D9F43A7C1.524


PRP results:
No PRP results for M6988271


P-1 factor-bounds graph:
B1 = 2000000, B2 = 241618650 (P-1 stage 2)
B1 = 2000000, B2 = 58000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 445000, B2 = 13572500 (P-1 stage 2)
B1 = 445000 (P-1 stage 1)
B1 = 25000, B2 = 87500 (P-1 stage 2)
B1 = 25000 (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: 67.7
ECM T-Level=1.15 ~= -13-bit
250
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270
280
Last modified: 2023-03-23T17:39:31+00:00