is 2 3256987 - 1
has 980451 decimal digits
takes 0.342 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LAD3B3963212B79B6double-checked
PRP37B956BC0DF55554verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26818.300667.6471%40000001500000001.82068.7755%20.121270.4862%2.8391%
PrimeNet2600.047263.3333%140002600000.00422.7719%0.051364.3497%1.0164%
GPU722641.092865.6250%160002800000.00461.6555%1.097566.1941%0.5691%
Difference+4+17.2078+2.0221%+3984000+149720000+1.8159+7.1200%+19.0237+4.2921%+4.2921%

Known prime factors (1 factor, 92.4 bits, 0.00283834% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
325698767386539489112736811537268732892.4451034491993506770779428
22 × 3 × 72 × 17 × 509 × 911 × 3677 × 60697541
2020-08-26367760697541543,103,7000.50410.9406

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2009-07-05T09:06:00Carsten Kossendeydurandal15000191250---0.004--0.785%
2011-09-13T15:37:00harleeP4_2600600001050000---0.017--1.929%
2014-06-11T02:11:00Jocelyn LaroucheManual testing7970779707---0.012--0.754%
2014-10-07T22:12:00Jocelyn LaroucheManual testing9941499414---0.015--0.861%
2016-01-18T12:25:10Jocelyn LaroucheManual testing41580041580006---0.094--3.697%
2020-08-26T04:58:07mikrMSI4000000150000000122892.4451.8210.6843.6418.776%
2021-01-18T13:43:04Jocelyn LaroucheManual testing44580032569876---0.091--3.513%
2022-01-06T11:34:48Jocelyn LaroucheManual testing1297196116447100-
skipped known factor: 6738653948911273681153726873
--1.153--7.696%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2001-07-29T00:00:00ANONYMOUSv4_computers21260--0.047--
2009-04-03T10:33:00S485122USB-Z260261--0.047--
2011-09-16T21:21:00markrManual testing21262--0.189--
2013-01-03T08:49:00dbaughManual testing262263--0.301--
2015-02-18T11:41:00VictordeHollanderManual testing263264--0.603--
2015-02-18T11:41:00VictordeHollanderManual testing264265--1.147--
2015-06-28T13:57:00ThaManual testing265266--2.294--
2021-02-21T11:36:42Jocelyn LaroucheManual testing265266--2.294--
2021-02-22T09:03:45Jocelyn LaroucheManual testing266267--4.589--
2017-03-30T02:15:54Gordon SpenceManual testing266267--4.589--
2019-01-07T14:44:14TJAOIManual testing267268--9.177--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.181 GHz-days
Estimated T-Level:0.750
DigitsB1CurvesCompleteFacMiss
201100015 / 1000.15086.006%
255000015 / 2800.05494.775%

New Calculation Method

Total ECM effort:2.181 GHz-days
Estimated T-Level:0.750
DigitsB1CompleteFacMiss
20110000.48461.639%
25500000.04495.721%
302500000.00399.731%


ECM Summary

B1B2factorcurvesGHz-days
500005000000152.181


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-06-06T00:00:00ANONYMOUSv4_computersAD3B3963212B79B60.342
2009-04-02T18:46:00ANONYMOUScomputerAD3B3963212B79B60.342


PRP results:
dateuseridcompidcofactorsres64PRP
2020-08-26T21:08:22jvang3600
6738653948911273681153726873
37B956BC0DF55554no


P-1 factor-bounds graph:
B1 = 4000000, B2 = 150000000 (P-1 stage 2)
B1 = 1297196, B2 = 116447100 (P-1 stage 2)
B1 = 4000000 (P-1 stage 1)
B1 = 1297196 (P-1 stage 1)
B1 = 415800, B2 = 4158000 (P-1 stage 2)
B1 = 445800, B2 = 3256987 (P-1 stage 2)
B1 = 445800 (P-1 stage 1)
B1 = 415800 (P-1 stage 1)
B1 = 60000, B2 = 1050000 (P-1 stage 2)
B1 = 99414 (P-1 stage 1)
B1 = 79707 (P-1 stage 1)
B1 = 60000 (P-1 stage 1)
B1 = 15000, B2 = 191250 (P-1 stage 2)
B1 = 15000 (P-1 stage 1)
102
103
104
105
106
107
102
103
104
105
106
107
108
109
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
250
260
270
280
290
2100
Last modified: 2022-01-06T11:34:48+00:00