is 2 2143847 - 1
has 645363 decimal digits
takes 0.141 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L8878EA6AE6D2AD73double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26827.802867.6471%25000001250000000.87467.9146%28.677470.2077%2.5606%
PrimeNet2580.017962.0690%90001700000.00172.7323%0.019663.1053%1.0364%
GPU722620.286664.5161%100001500000.00171.4881%0.288265.0442%0.5280%
Difference+6+27.5162+3.1309%+2490000+124850000+0.8730+6.4266%+28.3892+5.1635%+5.1635%

Known prime factors (1 factor, 90.3 bits, 0.00421164% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
214384715146941652021423979925067032890.291353265453458698871233
11 × 13 × 2470387786424467631
2020-07-01132470387786424467631140,073,0731.283e+102.397e+10

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-03-07T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.225%
2010-11-03T01:56:00Jocelyn LaroucheManual testing2000020000---0.002--0.254%
2010-12-30T22:20:00Jocelyn LaroucheManual testing3000030000---0.003--0.353%
2011-01-13T23:58:00Jocelyn LaroucheManual testing5000050000---0.005--0.512%
2011-01-21T05:41:00James Heinrichi7-9201300002632500---0.025--2.654%
2014-10-28T23:25:00Jocelyn LaroucheManual testing159939159939---0.015--1.044%
2016-06-06T01:26:58Jocelyn LaroucheManual testing17593252650006---0.043--3.265%
2016-11-13T02:06:37Jocelyn Larouchelow 4M211118211118---0.020--1.209%
2017-04-22T17:25:10Jocelyn Larouchelow 4M35186435186406---0.050--3.301%
2017-04-27T04:20:45Jocelyn Larouchelow 4M42223642223606---0.060--3.521%
2017-11-08T09:25:59mikrMSI250000012500000012---0.875--7.915%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-02-07T00:00:00ANONYMOUSv4_computers21258--0.018--
2016-02-23T16:29:07Mark RoseManual testing258260--0.054--
2009-01-05T08:05:00Sturle Sundefoster.ifi260261--0.072--
2009-01-08T05:37:00Sturle Sundeginjtje.ifi261262--0.143--
2013-09-07T11:35:00ramgeisManual testing262263--0.458--
2015-03-18T10:56:00VictordeHollanderManual testing263264--0.916--
2015-03-18T10:56:00VictordeHollanderManual testing264265--1.743--
2015-12-27T16:49:16ramgeisManual testing265266--3.486--
2016-10-29T15:24:11Gordon SpenceManual testing266267--6.971--
2019-04-15T13:43:12TJAOIManual testing267268--13.94--


ECM factoring results:

Old Calculation Method

Total ECM effort:7.935 GHz-days
Estimated T-Level:4.650
DigitsB1CurvesCompleteFacMiss
201100093 / 1000.93039.271%
255000093 / 2800.33271.696%

New Calculation Method

Total ECM effort:7.935 GHz-days
Estimated T-Level:4.650
DigitsB1CompleteFacMiss
20110003.0004.979%
25500000.27176.251%
302500000.01798.344%


ECM Summary

B1B2factorcurvesGHz-days
500005000000907.679
50000500000030.256


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-02-21T00:00:00ANONYMOUSv4_computers27161AD0FD7AFB__0.141
1999-05-30T00:00:00ANONYMOUSv4_computers8878EA6AE6D2AD730.141
1999-07-04T00:00:00ANONYMOUSv4_computers8878EA6AE6D2AD730.141
2018-04-08T01:07:08kkmrkkblmbrbkold8878EA6AE6D2AD730.141


PRP results:
dateuseridcompidcofactorsres64PRP
2020-07-01T10:51:43Christoph ZengerManual testing
1514694165202142397992506703
2072F2B02D44BF51no
2020-07-01T10:59:46CrypticClueManual testing
1514694165202142397992506703
2072F2B02D44BF51no


P-1 factor-bounds graph:
B1 = 2500000, B2 = 125000000 (P-1 stage 2)
B1 = 2500000 (P-1 stage 1)
B1 = 422236, B2 = 4222360 (P-1 stage 2)
B1 = 351864, B2 = 3518640 (P-1 stage 2)
B1 = 175932, B2 = 5265000 (P-1 stage 2)
B1 = 422236 (P-1 stage 1)
B1 = 351864 (P-1 stage 1)
B1 = 130000, B2 = 2632500 (P-1 stage 2)
B1 = 211118 (P-1 stage 1)
B1 = 175932 (P-1 stage 1)
B1 = 159939 (P-1 stage 1)
B1 = 130000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 20000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-07-01T10:59:46+00:00