is 2 1952851 - 1
has 587867 decimal digits
takes 0.106 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LF65610AC5C83C0E9double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26830.522069.1176%320000001027202274046.403415.5785%76.925473.9286%4.8110%
PrimeNet2580.019763.7931%80001400000.00122.4675%0.020964.6865%0.8934%
GPU722620.314666.1290%8000900000.00101.1535%0.315666.5197%0.3907%
Difference+6+30.2074+2.9886%+31992000+10271932740+46.4024+14.4250%+76.6098+7.4089%+7.4089%

Known prime factors:
No known factors for M1952851

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2011-05-16T18:42:00kurlyhex100000030000000---0.203--5.697%
2018-01-15T00:57:39Jocelyn Larouchelow 4M19528513000000012---0.274--6.051%
2018-02-12T21:00:12Jocelyn Larouchelow 4M19528516000000012---0.402--6.835%
2018-03-02T23:08:40Jocelyn Larouchelow 4M195285112000000012---0.660--7.626%
2018-05-10T11:54:31Jocelyn Larouchelow 4M195285119528510012---0.982--8.186%
2018-11-26T12:54:02Jocelyn LaroucheManual testing195285124410637512---1.191--8.444%
2022-08-01T14:14:48RichD0Linux-5b3200000010272022740---46.40--15.578%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-12-21T00:00:00Stephen Woodv4_computers21258--0.020--
2016-02-23T16:28:59Mark RoseManual testing258260--0.059--
2010-01-17T16:42:00S485122USB-W260261--0.079--
2016-02-23T16:28:59Mark RoseManual testing261262--0.157--
2011-08-27T22:19:00GrunwalderGIMPManual testing21263--0.817--
2016-02-23T16:28:59Mark RoseManual testing262263--0.503--
2015-04-23T21:39:00lycornManual testing263264--1.005--
2015-04-23T21:40:00lycornManual testing264265--1.913--
2015-09-06T20:47:00ramgeisManual testing265266--3.827--
2018-02-12T20:05:02TJAOIManual testing266267--7.653--
2019-05-13T00:32:11chuenkitManual testing267268--15.31--


ECM factoring results:

Old Calculation Method

Total ECM effort:18.016 GHz-days
Estimated T-Level:24.464
DigitsB1CurvesCompleteFacMiss
2011000250 / 1002.5008.106%
2550000250 / 2800.89340.883%

New Calculation Method

Total ECM effort:18.016 GHz-days
Estimated T-Level:24.464
DigitsB1CompleteFacMiss
20110009.7700.006%
25500000.90740.365%
302500000.05794.425%
3510000000.00399.732%


ECM Summary

B1B2factorcurvesGHz-days
50000500000019813.78
50000545000070.505
50000675000070.556
500007500000383.177


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-10T00:00:00Stephen Woodv4_computersF65610AC5C83C0E90.106
2015-07-06T20:16:00MadPooManual testingF65610AC5C83C0E90.106


PRP results:
No PRP results for M1952851


P-1 factor-bounds graph:
B1 = 32000000, B2 = 10272022740 (P-1 stage 2)
B1 = 32000000 (P-1 stage 1)
B1 = 1952851, B2 = 244106375 (P-1 stage 2)
B1 = 1952851, B2 = 195285100 (P-1 stage 2)
B1 = 1952851, B2 = 120000000 (P-1 stage 2)
B1 = 1952851, B2 = 60000000 (P-1 stage 2)
B1 = 1952851, B2 = 30000000 (P-1 stage 2)
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1952851 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-08-01T14:14:48+00:00