is 2 4057873 - 1
has 1221542 decimal digits
takes 0.506 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 L-L tests remaining
ResidueStatus
L-LA8FBC5153264CB89double-checked
PRPD35ED44260272432

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual27058.885768.5714%2237739626566811.00006.3405%59.885770.5641%1.9927%
PrimeNet2610.075763.9344%160003200000.00592.7349%0.081664.9208%0.9864%
GPU722651.797966.1538%220003600000.00731.7538%1.805266.7474%0.5936%
Difference+5+57.0878+2.4176%+2215739+62296681+0.9927+4.5867%+58.0805+3.8167%+3.8167%

Known prime factors (1 factor, 73.2 bits, 0.00180384% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
4057873108311642631176873713612373.1981334586403162160
24 × 5 × 7951 × 2098142377
2021-06-2979512098142377926.5020.67438.612

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2009-07-17T22:40:00Carsten Kossendeydurandal20000300000---0.006--0.771%
2011-07-23T13:43:00harleeP4_260040000580000---0.013--1.175%
2013-07-02T07:04:00Squeeky_SquirrelP4_26001200002310000---0.043--2.206%
2018-12-16T10:09:22Ismo Laitela6600K22377396265668112---1.000--6.340%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-06-29T16:22:50ATH5960X250000017000000027P+12373.1982.032


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-01-10T00:00:00ANONYMOUSv4_computers?260--0.019--
1999-03-15T00:00:00ANONYMOUSv4_computers?260--0.019--
2001-08-12T00:00:00ANONYMOUSv4_computers?261--0.038--
2010-10-18T20:28:00Grant McCrackenhome261262--0.076--
2011-07-01T19:07:00GrunwalderGIMPManual testing21263--0.393--
2016-02-23T16:29:47Mark RoseManual testing262263--0.242--
2013-08-19T07:33:00JayderManual testing263264--0.484--
2013-10-27T04:43:00David CampeauManual testing264265--0.921--
2015-05-21T23:03:00snme2pm1Manual testing265266--1.842--
2016-09-25T03:33:05kkmrkkblmbrbkManual testing266267--3.683--
2018-11-03T05:35:17YxinityManual testing267268--7.366--
2020-11-30T19:24:24mikrManual testing268269--14.73--
2020-11-30T19:24:24mikrManual testing269270--29.46--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.166 GHz-days
Estimated T-Level:0.600
DigitsB1CurvesCompleteFacMiss
201100012 / 1000.12088.638%
255000012 / 2800.04395.797%

New Calculation Method

Total ECM effort:2.166 GHz-days
Estimated T-Level:0.600
DigitsB1CompleteFacMiss
20110000.38767.903%
25500000.03596.562%
302500000.00299.785%


ECM Summary

B1B2factorcurvesGHz-days
500005000000122.166


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-04-21T00:00:00ANONYMOUSv4_computersA8FBC5153264CB890.506
1999-01-10T00:00:00ANONYMOUSv4_computersA8FBC5153264CB890.506
1999-03-15T00:00:00ANONYMOUSv4_computersA8FBC5153264CB890.506
2000-01-25T00:00:00ANONYMOUSv4_computersA8FBC5153264CB890.506


PRP results:
dateuseridcompidcofactorsres64PRP
2021-07-01T15:41:26kutensarcturus
10831164263117687371361
D35ED44260272432no


P-1 factor-bounds graph:
B1 = 2500000, B2 = 170000000 (P+1 stage 2)
B1 = 2237739, B2 = 62656681 (P-1 stage 2)
B1 = 2500000 (P+1 stage 1)
B1 = 2237739 (P-1 stage 1)
B1 = 120000, B2 = 2310000 (P-1 stage 2)
B1 = 120000 (P-1 stage 1)
B1 = 40000, B2 = 580000 (P-1 stage 2)
B1 = 40000 (P-1 stage 1)
B1 = 20000, B2 = 300000 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
102
103
104
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102
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104
105
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1010
TF factor-bounds graph:
270
269
268
267
266
265
264
263
262
261
260
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270
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2100
Last modified: 2021-07-01T15:41:26+00:00