is 2 1977721 - 1
has 595354 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-L8BD5C0A72A24D085double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual271241.731970.4225%19777212472151251.46246.6140%243.194372.3788%1.9562%
PrimeNet2580.019463.7931%80001400000.00142.4735%0.020964.6887%0.8956%
GPU722620.310666.1290%80001000000.00121.1969%0.311966.5344%0.4054%
Difference+9+241.4213+4.2935%+1969721+247115125+1.4611+5.4171%+242.8824+5.8444%+5.8444%

Known prime factors (1 factor, 82.0 bits, 0.00414435% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
197772147156714134300748652099132581.9641192198346842167036
22 × 34 × 23 × 78593 × 2035597001
2020-04-02785932035597001317,08910.58019.748

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2011-02-25T05:26:00kurlyslice100000030000000---0.246--4.323%
2018-01-23T13:04:03Jocelyn Larouchelow 4M19777213000000012---0.334--4.646%
2018-02-14T12:53:58Jocelyn Larouchelow 4M19777216000000012---0.490--5.282%
2018-03-06T12:48:08Jocelyn Larouchelow 4M197772112000000012---0.802--5.928%
2018-05-28T10:19:12Jocelyn Larouchelow 4M197772119777210012---1.206--6.401%
2018-11-26T12:53:53Jocelyn LaroucheManual testing197772124721512512---1.462--6.614%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-01-02T00:00:00ANONYMOUSv4_computers21258--0.019--
2016-02-23T16:29:01Mark RoseManual testing258260--0.058--
2009-12-23T06:27:00S485122USB-W260261--0.078--
2016-02-23T16:29:01Mark RoseManual testing261262--0.155--
2011-09-03T15:11:00GrunwalderGIMPManual testing21263--0.807--
2016-02-23T16:29:01Mark RoseManual testing262263--0.496--
2015-03-17T13:10:00lycornManual testing263264--0.993--
2015-03-17T13:10:00lycornManual testing264265--1.889--
2015-09-10T08:47:00ramgeisManual testing265266--3.778--
2018-03-08T06:00:50YxinityManual testing266267--7.557--
2018-03-08T06:00:50YxinityManual testing267268--15.11--
2018-03-08T06:00:50YxinityManual testing268269--30.23--
2018-03-08T06:00:50YxinityManual testing269270--60.46--
2018-06-11T14:43:00ramgeisManual testing270271--120.9--


ECM factoring results:

Old Calculation Method

Total ECM effort:8.024 GHz-days
Estimated T-Level:4.750
DigitsB1CurvesCompleteFacMiss
201100095 / 1000.95038.490%
255000095 / 2800.33971.185%

New Calculation Method

Total ECM effort:8.024 GHz-days
Estimated T-Level:4.750
DigitsB1CompleteFacMiss
20110003.0654.668%
25500000.27775.808%
302500000.01798.309%


ECM Summary

B1B2factorcurvesGHz-days
500005000000937.856
50000500000020.169


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-02-21T00:00:00ANONYMOUSv4_computers8BD5C0A72A24D0850.130
2015-07-12T18:10:00MadPooManual testing8BD5C0A72A24D0850.130


PRP results:
dateuseridcompidcofactorsres64PRP
2020-04-02T12:21:30CrypticCluecruncher
4715671413430074865209913
4A2DF5A42D67536Bno
2020-04-03T11:02:39marssystemssystem11
4715671413430074865209913
4A2DF5A42D67536Bno


P-1 factor-bounds graph:
B1 = 1977721, B2 = 247215125 (P-1 stage 2)
B1 = 1977721, B2 = 197772100 (P-1 stage 2)
B1 = 1977721, B2 = 120000000 (P-1 stage 2)
B1 = 1977721, B2 = 60000000 (P-1 stage 2)
B1 = 1977721, B2 = 30000000 (P-1 stage 2)
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1977721 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
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1010
TF factor-bounds graph:
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2100
Last modified: 2020-04-03T11:02:39+00:00