is 2 1938887 - 1
has 583664 decimal digits
takes 0.105 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L4C1B9C3299F3E337double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26715.325268.6567%1415608141560800.16605.5755%15.491270.4043%1.7475%
PrimeNet2580.019863.7931%80001400000.00122.4640%0.021064.6853%0.8921%
GPU722620.316966.1290%8000900000.00101.1517%0.317866.5191%0.3901%
Difference+5+15.0084+2.5277%+1407608+14066080+0.1650+4.4238%+15.1734+3.8851%+3.8851%

Known prime factors (1 factor, 82.3 bits, 0.00424492% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
193888759707271158164107155821612582.3041539730555678698840
23 × 32 × 5 × 23 × 185957796579553
2017-06-0123185957796579553715,110796,9691,488,515

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2012-01-27T19:07:00markrtiny2750006000000---0.046--3.946%
2015-10-08T11:15:52Bruno Victal5820K-linux5000001500000012---0.101--5.104%
2016-12-16T01:10:43Jocelyn Larouchelow 4M568903568903---0.045--2.124%
2016-12-18T04:24:51Jocelyn Larouchelow 4M682683682683---0.054--2.288%
2016-12-24T21:06:39Jocelyn Larouchelow 4M819219819219---0.064--2.458%
2017-01-04T23:07:21Jocelyn Larouchelow 4M983062983062---0.077--2.636%
2017-01-22T06:40:05Jocelyn Larouchelow 4M11796741179674---0.093--2.820%
2017-04-07T19:58:15Jocelyn Larouchelow 4M14156081415608012---0.166--5.576%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-12-21T00:00:00ANONYMOUSv4_computers21258--0.020--
2016-02-23T16:28:59Mark RoseManual testing258260--0.059--
2010-01-30T08:11:00S485122USB-W260261--0.079--
2016-02-23T16:28:59Mark RoseManual testing261262--0.158--
2011-08-27T22:21:00GrunwalderGIMPManual testing21263--0.823--
2016-02-23T16:28:59Mark RoseManual testing262263--0.506--
2015-05-07T16:29:00lycornManual testing263264--1.013--
2015-05-07T16:29:00lycornManual testing264265--1.927--
2015-09-05T13:49:00ramgeisManual testing265266--3.854--


ECM factoring results:

Old Calculation Method

Total ECM effort:20.886 GHz-days
Estimated T-Level:24.589
DigitsB1CurvesCompleteFacMiss
2011000257 / 1002.5707.555%
2550000257 / 2800.91839.872%

New Calculation Method

Total ECM effort:20.886 GHz-days
Estimated T-Level:24.589
DigitsB1CompleteFacMiss
20110009.0350.012%
25500000.80444.773%
302500000.05095.140%
3510000000.00299.771%


ECM Summary

B1B2factorcurvesGHz-days
500005000000372.573
50000500000020.139
50000675000070.555
50000750000021117.62


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-15T00:00:00ANONYMOUSv4_computers4C1B9C3299F3E3370.105
2015-07-12T18:10:00MadPooManual testing4C1B9C3299F3E3370.105


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-28T13:09:03alpertronManual testing
5970727115816410715582161
72FC3C667482ED__no
2017-10-20T11:08:58Oliver KruseThreadripper
5970727115816410715582161
72FC3C667482ED__no


P-1 factor-bounds graph:
B1 = 1415608, B2 = 14156080 (P-1 stage 2)
B1 = 1415608 (P-1 stage 1)
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 1179674 (P-1 stage 1)
B1 = 983062 (P-1 stage 1)
B1 = 819219 (P-1 stage 1)
B1 = 682683 (P-1 stage 1)
B1 = 275000, B2 = 6000000 (P-1 stage 2)
B1 = 568903 (P-1 stage 1)
B1 = 500000 (P-1 stage 1)
B1 = 275000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-04-07T09:50:31+00:00