is 2 6908249 - 1
has 2079591 decimal digits
takes 1.506 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L087B9F16DC19FE9Bdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.433668.0556%40000004143239108.33317.9700%146.766770.6015%
Target2674.301265.6716%450009000000.02902.2357%4.330266.4391%
Difference+5+134.1324+2.3839%+3955000+413423910+8.3042+5.7343%+142.4365+4.1624%

Known prime factors:
No known factors for M6908249

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-08-24ANONYMOUSv4_computers30000270000---0.014--0.704%
2002-06-23ANONYMOUSv4_computers30000270000---0.014--0.704%
2011-11-21James Heinrichi7-9201300002665000---0.085--1.985%
2020-01-09takahashivaio6000001200000012---0.386--3.581%
2021-11-21Seth_TrManual testing400000011000000012---3.091--6.530%
2021-11-30Seth_TrManual testing4000000414323910---8.333--7.970%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05Mark Dv4_computers21261--0.044--
1998-07-21ANONYMOUSv4_computers21262--0.089--
2005-07-01ANONYMOUSv4_computers21263--0.231--
2014-02-09NesowaManual testing263264--0.284--
2014-02-18lycornManual testing264265--0.541--
2015-06-21VictordeHollanderManual testing265266--1.082--
2016-04-01Gordon SpenceManual testing266267--2.163--
2018-05-23ramgeisManual testing267268--4.327--
2020-01-03mnd9Manual testing268269--8.654--
2020-12-21takahashiManual testing269270--17.31--
2021-08-11SRBaseManual testing270271--34.61--
2021-09-28SRBaseManual testing271272--69.23--


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)
1999-04-02ANONYMOUSv4_computersC08634110B93ED__1.506
1999-07-04ANONYMOUSv4_computers087B9F16DC19FE9B1.506
2001-09-16ANONYMOUSv4_computers087B9F16DC19FE9B1.506
2002-06-23ANONYMOUSv4_computers087B9F16DC19FE9B1.506


PRP results:
No PRP results for M6908249


P-1 factor-bounds graph:
B1 = 4000000, B2 = 414323910 (P-1 stage 2)
B1 = 4000000, B2 = 110000000 (P-1 stage 2)
B1 = 4000000 (P-1 stage 1)
B1 = 600000, B2 = 12000000 (P-1 stage 2)
B1 = 600000 (P-1 stage 1)
B1 = 130000, B2 = 2665000 (P-1 stage 2)
B1 = 130000 (P-1 stage 1)
B1 = 30000, B2 = 270000 (P-1 stage 2)
B1 = 30000 (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
261
this exponent TF target: 67
TF double-checked to: 67.7
ECM T-Level=1.15 ~= -13-bit
250
260
270
280
Last modified: 2023-03-23T17:39:31+00:00