is 2 2241917 - 1
has 674885 decimal digits
takes 0.147 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LA78EB797B31441F3double-checked
PRP9C4FD60173FD1BD3verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26826.586667.6471%2000000650000000.51797.0406%27.104569.9249%2.2778%
PrimeNet2580.017162.0690%100001800000.00182.8730%0.019063.1587%1.0898%
GPU722620.274064.5161%110001900000.00201.6588%0.276065.1047%0.5886%
Difference+6+26.3125+3.1309%+1989000+64810000+0.5159+5.3818%+26.8285+4.8202%+4.8202%

Known prime factors (1 factor, 73.4 bits, 0.00327261% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2241917121982483646179814146872373.3692720495086262779
7 × 100981 × 3848666137
2020-08-1410098138486661371,133.820.00037.337

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-03-27T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.228%
2010-11-10T22:07:00Jocelyn LaroucheManual testing3000030000---0.003--0.356%
2011-01-07T20:14:00markrtiny1000002050000---0.020--2.395%
2014-08-25T00:29:00ANONYMOUSManual testing128629128629---0.012--0.933%
2015-12-03T19:16:30Alexander DubrovinManual testing100000060000006---0.121--4.167%
2016-01-17T18:58:57Alexander DubrovinManual testing20000006500000012---0.518--7.041%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:09Mark RoseManual testing21260--0.069--
2009-01-11T15:28:00Sturle Sundehomilius.ifi260261--0.069--
2012-05-03T08:47:00Sebastian HornbostelManual testing261262--0.137--
2013-08-21T07:39:00David CampeauManual testing262263--0.438--
2015-03-10T10:44:00VictordeHollanderManual testing263264--0.876--
2015-03-10T10:44:00VictordeHollanderManual testing264265--1.667--
2015-10-26T11:50:57ramgeisManual testing265266--3.333--
2016-12-30T02:46:28Gordon SpenceManual testing266267--6.666--
2019-04-01T13:34:47TJAOIManual testing267268--13.33--


ECM factoring results:

Old Calculation Method

Total ECM effort:8.325 GHz-days
Estimated T-Level:4.850
DigitsB1CurvesCompleteFacMiss
201100097 / 1000.97037.724%
255000097 / 2800.34670.677%

New Calculation Method

Total ECM effort:8.325 GHz-days
Estimated T-Level:4.850
DigitsB1CompleteFacMiss
20110003.1294.376%
25500000.28375.367%
302500000.01798.274%


ECM Summary

B1B2factorcurvesGHz-days
500005000000968.239
50000500000010.086


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-15T00:00:00ANONYMOUSv4_computersA78EB797B31441F30.147
2018-04-21T23:35:02kkmrkkblmbrbkoldA78EB797B31441F30.147


PRP results:
dateuseridcompidcofactorsres64PRP
2020-08-14T21:23:33George Woltmanx64-debug
12198248364617981414687
9C4FD60173FD1BD3no


P-1 factor-bounds graph:
B1 = 2000000, B2 = 65000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 1000000, B2 = 6000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 100000, B2 = 2050000 (P-1 stage 2)
B1 = 128629 (P-1 stage 1)
B1 = 100000 (P-1 stage 1)
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
109
1010
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
250
260
270
280
290
2100
Last modified: 2020-08-14T21:23:33+00:00