is 2 2081861 - 1
has 626703 decimal digits
takes 0.137 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L675CDF2C833CB4A3double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26714.272868.6567%500000150000000.12305.1478%14.395870.2702%1.6135%
PrimeNet2580.018463.7931%90001600000.00162.6734%0.020164.7611%0.9680%
GPU722620.295166.1290%90001400000.00151.3991%0.296666.6029%0.4739%
Difference+5+13.9777+2.5277%+491000+14860000+0.1214+3.7487%+14.0991+3.6673%+3.6673%

Known prime factors (1 factor, 94.6 bits, 0.00454285% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2081861295232750622626084114296324392994.5767090597081712613957279
3 × 112 × 29 × 30431 × 194827 × 113609021
2015-12-181948271136090211.968e+90.60771.1022

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-02-27T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.276%
2009-07-26T11:38:00harleeP4_260020000260000---0.003--1.019%
2010-12-28T02:15:00Jocelyn LaroucheManual testing3000030000---0.003--0.414%
2011-01-07T22:30:00Jocelyn LaroucheManual testing5000050000---0.005--0.595%
2011-01-24T13:46:00James HeinrichQ66001350002936250---0.027--3.058%
2016-03-16T13:42:46alpertronManual testing5000001500000012---0.123--5.148%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-07-26T00:00:00ANONYMOUSv4_computers21258--0.018--
2016-02-23T16:29:05Mark RoseManual testing258260--0.055--
2009-01-03T04:34:00Sturle Sundekinner.ifi260261--0.074--
2012-03-17T18:47:00Sebastian HornbostelManual testing261262--0.148--
2013-09-02T08:36:00ramgeisManual testing262263--0.472--
2015-03-31T15:56:00VictordeHollanderManual testing263264--0.943--
2015-03-31T15:56:00VictordeHollanderManual testing264265--1.795--
2015-11-05T09:47:18ramgeisManual testing265266--3.589--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.040 GHz-days
Estimated T-Level:1.150
DigitsB1CurvesCompleteFacMiss
201100023 / 1000.23079.361%
255000023 / 2800.08292.100%

New Calculation Method

Total ECM effort:2.040 GHz-days
Estimated T-Level:1.150
DigitsB1CompleteFacMiss
20110000.74347.566%
25500000.06793.514%
302500000.00499.588%


ECM Summary

B1B2factorcurvesGHz-days
10000100000050.085
500005000000221.870
50000500000010.085


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2015-11-14T18:08:36MadPooManual testing675CDF2C833CB4A30.137


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-30T15:31:07alpertronManual testing
29523275062262608411429632439
CFC97E41286515__no
2017-10-21T07:50:38Oliver KruseThreadripper
29523275062262608411429632439
CFC97E41286515__no


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
B1 = 135000, B2 = 2936250 (P-1 stage 2)
B1 = 135000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 20000, B2 = 260000 (P-1 stage 2)
B1 = 30000 (P-1 stage 1)
B1 = 20000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
102
103
104
105
106
102
103
104
105
106
107
108
109
TF factor-bounds graph:
267
266
265
264
263
262
261
260
258
250
260
270
280
290
2100
Last modified: 2022-03-22T09:51:33+00:00