is 2 2638897 - 1
has 794388 decimal digits
takes 0.204 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LBCCF8BE844E28048double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26711.260067.1642%2000000600000000.57797.6896%11.837969.6891%2.5250%
PrimeNet2590.029162.7119%110002000000.00242.7023%0.031563.7195%1.0076%
GPU722630.604865.0794%130002000000.00261.5735%0.607465.6288%0.5495%
Difference+4+10.6552+2.0848%+1987000+59800000+0.5753+6.1162%+11.2305+4.0603%+4.0603%

Known prime factors (1 factor, 64.6 bits, 0.00244982% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2638897289103638536115999272064.6485477736314379
3 × 7 × 47 × 4651 × 1193267
2010-06-23465111932672.62950.00780.0136

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-31T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.295%
2009-06-21T13:42:00harleeP4_260030000420000---0.006--1.390%
2019-07-04T12:47:09alpertronManual testing20000006000000012-
skipped known factor: 28910363853611599927
--0.578--7.690%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21259--0.029--
2022-03-11T04:28:50LordJuliusManual testing21260--0.058--
2009-01-27T19:58:00Sturle Sundekinner.ifi260261--0.058--


ECM factoring results:

Old Calculation Method

Total ECM effort:0.310 GHz-days
Estimated T-Level:0.150
DigitsB1CurvesCompleteFacMiss
20110003 / 1000.03097.030%
25500003 / 2800.01198.932%

New Calculation Method

Total ECM effort:0.310 GHz-days
Estimated T-Level:0.150
DigitsB1CompleteFacMiss
20110000.11589.102%
25500000.01198.938%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
50000500000030.310


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-23T00:00:00ANONYMOUSv4_computersBCCF8BE844E280480.204


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-18T20:57:51Oliver KruseGTX-3
28910363853611599927
31B951C7E24BEF__no
2017-12-03T01:57:50kkmrkkblmbrbkc4.xlarge
28910363853611599927
31B951C7E24BEF__no


P-1 factor-bounds graph:
B1 = 2000000, B2 = 60000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 30000, B2 = 420000 (P-1 stage 2)
B1 = 30000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
102
103
104
105
106
107
102
103
104
105
106
107
108
TF factor-bounds graph:
267
261
260
259
250
260
270
280
290
2100
Last modified: 2022-03-11T04:28:50+00:00