is 2 6378517 - 1
has 1920125 decimal digits
takes 1.130 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L3F7CEE06F79F111Ddouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272149.930468.0556%400000018004726740253.048112.0521%402.978571.9055%
Target2662.315365.1515%4500080000000.12292.5712%2.438366.0476%
Difference+6+147.6151+2.9040%+3955000+17996726740+252.9251+9.4808%+400.5402+5.8580%

Known prime factors (1 factor, 127.8 bits, 0.00200310% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
637851728978642458378656210040833550779951467339127.76822715815022816946486182316007608
23 × 3 × 292 × 283 × 22157 × 74047 × 1096031 × 2211532811
2023-04-24109603122115328112.624e+1031.22957.830

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-02-04ANONYMOUSv4_computers30000435000---0.013--0.807%
2014-10-18Nesowanewfs3900009750000---0.231--3.196%
2022-10-06takahashivaio250000050028510---1.308--5.437%
2023-04-19linamentU2K39999003999900---1.028--3.014%
2023-04-24linamentCyber40000001800472674039127.768253.02.261506.112.052%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-05ANONYMOUSv4_computers21262--0.096--
2016-02-23Mark RoseManual testing262263--0.154--
2014-08-17NesowaManual testing263264--0.308--
2014-08-20lycornManual testing264265--0.586--
2015-10-21snme2pm1Manual testing265266--1.172--
2016-04-08Gordon SpenceManual testing266267--2.343--
2018-06-04ramgeisManual testing267268--4.686--
2020-05-05takahashiManual testing268269--9.372--
2021-02-11takahashiManual testing269270--18.74--
2022-01-02mikrManual testing270271--37.49--
2022-07-31takahashiManual testing271272--74.98--


ECM factoring results:
Total ECM effort:1.617 GHz-days
Estimated T-Level:1.154
DigitsB1CompleteFacMiss
20110000.23179.392%
25500000.02197.887%
302500000.00199.865%


ECM Summary

B1B2factorcurvesGHz-days
50000500000061.617


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Paul Victor Novaresegilligan3F7CEE06F79F111D1.130
1999-09-14curtiscv4_computers3F7CEE06F79F111D1.130


PRP results:
dateuseridcompidcofactorsres64PRP
2023-04-24linamentCyber
289786424583786562100408335507799514673
576A992DF0548170no


P-1 factor-bounds graph:
B1 = 4000000, B2 = 18004726740 (P-1 stage 2)
B1 = 2500000, B2 = 50028510 (P-1 stage 2)
B1 = 4000000 (P-1 stage 1)
B1 = 3999900 (P-1 stage 1)
B1 = 2500000 (P-1 stage 1)
B1 = 390000, B2 = 9750000 (P-1 stage 2)
B1 = 390000 (P-1 stage 1)
B1 = 30000, B2 = 435000 (P-1 stage 2)
B1 = 30000 (P-1 stage 1)
103
104
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: 66
TF double-checked to: 67.9
ECM T-Level=1.15 ~= -13-bit
250
260
270
280
290
2100
2110
2120
2130
Last modified: 2023-07-11T14:45:05+00:00