is 2 822721 - 1
has 247664 decimal digits
takes 0.016 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L9699DF93AEC6F20Edouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26736.116670.1493%82272102468163000.61479.3905%36.731372.9524%2.8031%
PrimeNet2400.000050.0000%80003200000.000722.7539%0.000761.3769%11.3769%
GPU722440.000054.5455%140005500000.001317.5060%0.001362.5027%7.9573%
Difference+23+36.1166+15.6038%+8213210+246266300+0.6135-8.1155%+36.7301+10.4497%+10.4497%

Known prime factors (1 factor, 78.4 bits, 0.00952453% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
8227213879693660904715011423612478.360235784285371633580
22 × 5 × 11789214268581679
2016-06-16511789214268581679125,94518,601,08834,741,652

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-01-08T00:00:00ANONYMOUSv4_computers2000200000---0.000--0.205%
2002-02-10T00:00:00ANONYMOUSv4_computers4096409600---0.001--0.438%
2002-04-07T00:00:00ANONYMOUSv4_computers8192819200---0.002--0.789%
2002-05-18T00:00:00ANONYMOUSv4_computers163841638400---0.003--1.280%
2002-06-09T00:00:00ANONYMOUSv4_computers327683276800---0.006--1.919%
2002-11-24T00:00:00ANONYMOUSv4_computers655376553700---0.012--2.698%
2003-07-21T00:00:00ANONYMOUSv4_computers13107213107200---0.024--3.605%
2008-10-26T22:45:00markrManual testing100000020000000---0.059--5.253%
2008-10-29T23:36:00markrManual testing100000040000000---0.090--5.951%
2012-09-21T00:59:00Jocelyn LaroucheManual testing16454421645442---0.048--2.836%
2013-11-02T05:09:00David Campeaui5-2500k167000056780000---0.135--6.643%
2015-11-26T02:15:34Sid & AndyHand_In_The_Box822721024681630012---0.615--9.390%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2000-07-25T00:00:00ANONYMOUSv4_computers21255--0.006--
2001-02-04T00:00:00ANONYMOUSv4_computers21256--0.012--
2001-10-13T00:00:00ANONYMOUSv4_computers21257--0.023--
2003-08-31T00:00:00ANONYMOUSv4_computers21258--0.047--
2008-10-14T05:25:00Sturle Sundeaeronca.ifi258259--0.047--
2008-10-14T06:01:00Sturle Sundeaeronca.ifi259260--0.093--
2010-06-01T02:20:00Architects Cubedm1_tt260261--0.187--
2015-02-27T10:10:00TJAOIManual testing261262--0.373--
2015-09-28T01:02:15Gordon SpenceManual testing262263--1.193--
2015-09-28T01:02:15Gordon SpenceManual testing263264--2.386--
2016-02-23T08:31:35lycornManual testing264265--4.541--


ECM factoring results:

Old Calculation Method

Total ECM effort:10.744 GHz-days
Estimated T-Level:25.344
DigitsB1CurvesCompleteFacMiss
2011000293 / 1002.9305.262%
2550000293 / 2801.04635.053%
3025000044 / 6400.06993.351%

New Calculation Method

Total ECM effort:10.744 GHz-days
Estimated T-Level:25.344
DigitsB1CompleteFacMiss
201100013.5770.000%
25500001.50622.183%
302500000.12488.310%
3510000000.00899.163%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
5000050000002495.704
25000025000000445.040


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2015-04-11T15:53:00MadPooManual testing9699DF93AEC6F20E0.016


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-28T02:28:49Oliver KruseGTX-1
387969366090471501142361
21FDE38D63FF1B__no
2017-10-14T01:59:13Oliver KruseThreadripper21FDE38D63FF1B__no
2017-12-18T01:29:49ATHec2-1xf
387969366090471501142361
21FDE38D63FF1B__no
2020-04-21T14:02:00Oliver KruseAddPrpType5
387969366090471501142361
786D1932623F4C__no


P-1 factor-bounds graph:
B1 = 8227210, B2 = 246816300 (P-1 stage 2)
B1 = 8227210 (P-1 stage 1)
B1 = 1670000, B2 = 56780000 (P-1 stage 2)
B1 = 1000000, B2 = 40000000 (P-1 stage 2)
B1 = 1000000, B2 = 20000000 (P-1 stage 2)
B1 = 1670000 (P-1 stage 1)
B1 = 1645442 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 65537, B2 = 6553700 (P-1 stage 2)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 16384, B2 = 1638400 (P-1 stage 2)
B1 = 65537 (P-1 stage 1)
B1 = 8192, B2 = 819200 (P-1 stage 2)
B1 = 32768 (P-1 stage 1)
B1 = 4096, B2 = 409600 (P-1 stage 2)
B1 = 16384 (P-1 stage 1)
B1 = 2000, B2 = 200000 (P-1 stage 2)
B1 = 8192 (P-1 stage 1)
B1 = 4096 (P-1 stage 1)
B1 = 2000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-04-21T14:02:00+00:00