is 2 7939081 - 1
has 2389902 decimal digits
takes 1.817 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LD493D8C6988C6C9Cdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272120.459068.0556%30000008070112050146.822411.0657%267.281471.5904%
Target2673.742765.6716%5500060000000.12572.5637%3.868566.5517%
Difference+5+116.7162+2.3839%+2945000+8064112050+146.6967+8.5020%+263.4130+5.0387%

Known prime factors:
No known factors for M7939081

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-06-02ANONYMOUSv4_computers40000520000---0.022--0.973%
2012-09-06Squeeky_SquirrelT7500_22001000001900000---0.066--1.763%
2016-10-08Squeeky_Squirreli5-5250U_1600245000630875012---0.191--2.784%
2023-06-13ThaZ-17030000008070112050---146.8--11.066%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-09-27ANONYMOUSv4_computers21262--0.077--
1998-10-04ANONYMOUSv4_computers21263--0.201--
2013-10-02NesowaManual testing263264--0.247--
2014-01-04David CampeauManual testing264265--0.471--
2015-06-03VictordeHollanderManual testing265266--0.941--
2016-08-18Gordon SpenceManual testing266267--1.883--
2018-07-24ramgeisManual testing267268--3.765--
2020-02-07TJAOIManual testing268269--7.530--
2020-09-26-Anonymous-Manual testing269270--15.06--
2021-12-04mikrManual testing270271--30.12--
2023-08-29riccardo ubertiGPU72_TF271272--60.24--


ECM factoring results:
Total ECM effort:2.088 GHz-days
Estimated T-Level:1.154
DigitsB1CompleteFacMiss
20110000.23179.392%
25500000.02197.887%
302500000.00199.865%


ECM Summary

B1B2factorcurvesGHz-days
50000500000062.088


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2000-01-12ANONYMOUSv4_computersD493D8C6988C6C9C1.817
2002-06-15ANONYMOUSv4_computersD493D8C6988C6C9C1.817


PRP results:
No PRP results for M7939081


P-1 factor-bounds graph:
B1 = 3000000, B2 = 8070112050 (P-1 stage 2)
B1 = 3000000 (P-1 stage 1)
B1 = 245000, B2 = 6308750 (P-1 stage 2)
B1 = 245000 (P-1 stage 1)
B1 = 100000, B2 = 1900000 (P-1 stage 2)
B1 = 100000 (P-1 stage 1)
B1 = 40000, B2 = 520000 (P-1 stage 2)
B1 = 40000 (P-1 stage 1)
103
104
105
106
107
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
272
271
270
269
268
267
266
265
264
263
262
this exponent TF target: 67
TF double-checked to: 67.9
ECM T-Level=1.15 ~= -13-bit
250
260
270
280
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Last modified: 2023-10-02T12:12:48+00:00