is 2 3128401 - 1
has 941743 decimal digits
takes 0.266 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L7591D61D9BF91002double-checked
PRPBE76488FA46F1671verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26819.052867.6471%31284016374375704.651010.4098%23.703971.0149%3.3679%
PrimeNet2600.049163.3333%130002400000.00312.6466%0.052264.3037%0.9704%
GPU722641.137765.6250%150002400000.00341.5422%1.141166.1551%0.5301%
Difference+4+17.9151+2.0221%+3113401+637197570+4.6477+8.8677%+22.5627+4.8598%+4.8598%

Known prime factors (1 factor, 83.4 bits, 0.00266534% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
3128401126072469192562047692798412683.3822014966578654111920
24 × 5 × 449 × 56095951521551
2020-12-22449560959515215511,011,100377,177704,461

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2004-02-07T00:00:00ANONYMOUSv4_computers2048204800---0.002--0.251%
2009-07-03T00:50:00Carsten Kossendeyleela15000180000---0.003--0.764%
2011-08-31T08:06:00Squeeky_SquirrelT7500_22001050002152500---0.027--2.573%
2011-09-22T00:00:00ANONYMOUSv4_computers1000010000---0.001--0.148%
2016-10-01T13:07:00Squeeky_Squirreli5-5250U_1600195000546000012---0.059--3.526%
2018-07-17T23:14:17Jocelyn Larouchelow 4M6921442076432---0.095--3.211%
2018-07-18T06:34:20Jocelyn Larouchelow 4M6921442768576---0.099--3.479%
2018-07-18T23:15:58Jocelyn Larouchelow 4M6921444152864---0.109--3.861%
2018-12-15T08:14:47mikrMSI300000010000000012---1.022--8.055%
2021-01-18T13:43:03Jocelyn LaroucheManual testing72214431284016---0.105--3.605%
2021-11-22T00:58:58Jocelyn LaroucheManual testing31284013128401---0.386--3.766%
2021-12-19T09:29:29Jocelyn LaroucheManual testing3128401108997350---1.098--8.188%
2021-12-22T09:19:33Jocelyn LaroucheManual testing3128401637437570---4.651--10.410%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2001-05-06T00:00:00ANONYMOUSv4_computers21260--0.049--
2009-04-13T05:58:00S485122USB-A260261--0.049--
2011-11-13T18:56:00markroldgamer261262--0.098--
2013-01-07T13:56:00dbaughManual testing262263--0.314--
2015-02-11T09:10:00VictordeHollanderManual testing263264--0.628--
2015-02-11T09:10:00VictordeHollanderManual testing264265--1.194--
2015-06-14T13:51:00ThaManual testing265266--2.389--
2021-02-18T11:47:34Jocelyn LaroucheManual testing265266--2.389--
2021-02-18T21:10:23Jocelyn LaroucheManual testing266267--4.777--
2017-04-16T02:34:53Gordon SpenceManual testing266267--4.777--
2019-01-07T14:44:25TJAOIManual testing267268--9.55--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.808 GHz-days
Estimated T-Level:1.200
DigitsB1CurvesCompleteFacMiss
201100024 / 1000.24078.568%
255000024 / 2800.08691.772%

New Calculation Method

Total ECM effort:2.808 GHz-days
Estimated T-Level:1.200
DigitsB1CompleteFacMiss
20110000.77446.108%
25500000.07093.242%
302500000.00499.570%


ECM Summary

B1B2factorcurvesGHz-days
500005000000222.574
50000500000020.234


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-04-15T00:00:00ANONYMOUSv4_computers7591D61D9BF910020.266
1999-08-07T00:00:00ANONYMOUSv4_computers7591D61D9BF910020.266


PRP results:
dateuseridcompidcofactorsres64PRP
2020-12-23T07:44:00Niels_Mache_Nextcloudconf4-a
12607246919256204769279841
BE76488FA46F1671no


P-1 factor-bounds graph:
B1 = 3128401, B2 = 637437570 (P-1 stage 2)
B1 = 3128401, B2 = 108997350 (P-1 stage 2)
B1 = 3000000, B2 = 100000000 (P-1 stage 2)
B1 = 3128401 (P-1 stage 1)
B1 = 3000000 (P-1 stage 1)
B1 = 692144, B2 = 4152864 (P-1 stage 2)
B1 = 722144, B2 = 3128401 (P-1 stage 2)
B1 = 692144, B2 = 2768576 (P-1 stage 2)
B1 = 692144, B2 = 2076432 (P-1 stage 2)
B1 = 722144 (P-1 stage 1)
B1 = 692144 (P-1 stage 1)
B1 = 195000, B2 = 5460000 (P-1 stage 2)
B1 = 105000, B2 = 2152500 (P-1 stage 2)
B1 = 195000 (P-1 stage 1)
B1 = 105000 (P-1 stage 1)
B1 = 15000, B2 = 180000 (P-1 stage 2)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 10000 (P-1 stage 1)
B1 = 2048 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2021-12-22T09:19:33+00:00