is 2 1973857 - 1
has 594191 decimal digits
takes 0.130 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L54312E12338FCDB9double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual271242.205170.4225%19738572467321251.45956.6093%243.664772.3774%1.9549%
PrimeNet2580.019563.7931%80001400000.00142.4726%0.020964.6883%0.8952%
GPU722620.311266.1290%80001000000.00121.1964%0.312566.5343%0.4052%
Difference+9+241.8939+4.2935%+1965857+246632125+1.4583+5.4129%+243.3522+5.8431%+5.8431%

Known prime factors (1 factor, 76.3 bits, 0.00386339% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1973857903457740471267141218092376.25822885592534597672
23 × 11 × 257 × 1011920433967
2020-01-2025710119204339678,713.35,256.29,817.1

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2011-03-19T07:21:00kurlyhex100000030000000---0.246--4.322%
2018-01-20T15:39:31Jocelyn Larouchelow 4M19738573000000012---0.334--4.644%
2018-02-13T12:59:58Jocelyn Larouchelow 4M19738576000000012---0.490--5.280%
2018-03-05T13:35:46Jocelyn Larouchelow 4M197385712000000012---0.801--5.926%
2018-05-28T10:19:13Jocelyn Larouchelow 4M197385719738570012---1.203--6.397%
2018-11-26T12:53:54Jocelyn LaroucheManual testing197385724673212512---1.460--6.609%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-12-27T00:00:00ANONYMOUSv4_computers21258--0.019--
2016-02-23T16:29:01Mark RoseManual testing258260--0.058--
2009-12-28T23:05:00S485122USB-W260261--0.078--
2016-02-23T16:29:01Mark RoseManual testing261262--0.156--
2011-08-27T22:19:00GrunwalderGIMPManual testing21263--0.809--
2016-02-23T16:29:01Mark RoseManual testing262263--0.497--
2015-03-19T08:30:00lycornManual testing263264--0.995--
2015-03-19T08:31:00lycornManual testing264265--1.893--
2015-09-10T08:47:00ramgeisManual testing265266--3.786--
2018-03-23T04:44:40YxinityManual testing266267--7.572--
2018-03-23T04:44:40YxinityManual testing267268--15.14--
2018-03-23T04:44:40YxinityManual testing268269--30.29--
2018-03-23T04:44:40YxinityManual testing269270--60.57--
2018-06-15T12:19:12ramgeisManual testing270271--121.1--


ECM factoring results:

Old Calculation Method

Total ECM effort:5.658 GHz-days
Estimated T-Level:3.350
DigitsB1CurvesCompleteFacMiss
201100067 / 1000.67050.999%
255000067 / 2800.23978.685%

New Calculation Method

Total ECM effort:5.658 GHz-days
Estimated T-Level:3.350
DigitsB1CompleteFacMiss
20110002.16111.518%
25500000.19582.256%
302500000.01298.804%


ECM Summary

B1B2factorcurvesGHz-days
500005000000665.574
50000500000010.084


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-10T00:00:00ANONYMOUSv4_computers54312E12338FCDB90.130
2015-06-27T00:54:00MadPooManual testing54312E12338FCDB90.130


PRP results:
dateuseridcompidcofactorsres64PRP
2020-01-23T15:41:14mnd975211backdoor
90345774047126714121809
C6F452AAB220A88Dno
2020-01-24T08:37:55Luigi Morelli9800X
90345774047126714121809
C6F452AAB220A88Dno


P-1 factor-bounds graph:
B1 = 1973857, B2 = 246732125 (P-1 stage 2)
B1 = 1973857, B2 = 197385700 (P-1 stage 2)
B1 = 1973857, B2 = 120000000 (P-1 stage 2)
B1 = 1973857, B2 = 60000000 (P-1 stage 2)
B1 = 1973857, B2 = 30000000 (P-1 stage 2)
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1973857 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-03-31T10:59:41+00:00