is 2 6979871 - 1
has 2101151 decimal digits
takes 1.522 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LCF3CDA612C8E10BBdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272137.013168.0556%1000000028985646690502.307613.6835%639.320672.4267%
Target2674.257165.6716%450009000000.02902.2395%4.286066.4404%
Difference+5+132.7560+2.3839%+9955000+28984746690+502.2786+11.4440%+635.0346+5.9863%

Known prime factors:
No known factors for M6979871

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-12-22ANONYMOUSv4_computers3000030000---0.009--0.235%
2011-09-07Carsten Kossendeymother44500013683750---0.369--3.534%
2021-12-06Seth_TrManual testing20000002000000---0.632--2.397%
2022-09-30JayderBlack_Adder1000000028985646690---502.3--13.684%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-10-25ANONYMOUSv4_computers21262--0.088--
2005-08-16ANONYMOUSv4_computers21263--0.229--
2014-02-09NesowaManual testing263264--0.281--
2014-02-15lycornManual testing264265--0.535--
2015-07-03VictordeHollanderManual testing265266--1.071--
2016-04-26Gordon SpenceManual testing266267--2.141--
2018-02-27-Anonymous-Manual testing267268--4.282--
2020-04-10TJAOIManual testing268269--8.565--
2021-08-09takahashiManual testing269270--17.13--
2021-09-07SRBaseManual testing270271--34.26--
2021-10-10SRBaseManual testing271272--68.52--


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_computers44433D2E43EBB4__1.522
1999-07-27ANONYMOUSv4_computersCF3CDA612C8E10BB1.522
2002-01-08ANONYMOUSv4_computersCF3CDA612C8E10BB1.522


PRP results:
No PRP results for M6979871


P-1 factor-bounds graph:
B1 = 10000000, B2 = 28985646690 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
B1 = 2000000 (P-1 stage 1)
B1 = 445000, B2 = 13683750 (P-1 stage 2)
B1 = 445000 (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
1010
1011
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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280
Last modified: 2023-04-26T21:34:10+00:00