is 2 2125801 - 1
has 639930 decimal digits
takes 0.140 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L076A89FDEE37EA47double-checked
PRP3DC77C24A34E1767verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26828.038867.6471%25000001250000000.87467.9080%28.913470.2055%2.5585%
PrimeNet2580.018162.0690%90001600000.00162.6839%0.019763.0870%1.0180%
GPU722620.289064.5161%100001400000.00161.4549%0.290665.0324%0.5163%
Difference+6+27.7498+3.1309%+2490000+124860000+0.8730+6.4530%+28.6228+5.1731%+5.1731%

Known prime factors (1 factor, 88.5 bits, 0.00416153% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
21258014274619685424110085228077212788.466100541388526586215860
22 × 3 × 5 × 1675689808776436931
2021-03-215167568980877643693135,615,5278.704e+91.626e+10

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-08-08T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.224%
2009-08-03T19:24:00harleeP4_260020000265000---0.003--0.884%
2011-01-01T00:56:00Jocelyn LaroucheManual testing3000030000---0.003--0.352%
2011-01-11T22:56:00Jocelyn LaroucheManual testing5000050000---0.005--0.511%
2011-01-25T03:52:00James Heinrichi7-9201400003045000---0.028--2.778%
2016-06-26T03:50:56Jocelyn LaroucheManual testing210000609000012---0.051--3.463%
2017-08-19T15:19:14Jocelyn Larouchelow 4M42000042000006---0.060--3.510%
2017-08-30T00:32:08Jocelyn Larouchelow 4M50400050400006---0.072--3.736%
2017-09-06T12:58:29mikrMSI250000012500000012---0.875--7.908%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-04-13T00:00:00ANONYMOUSv4_computers21258--0.018--
1999-06-15T00:00:00ANONYMOUSv4_computers21258--0.018--
2016-02-23T16:29:05Mark RoseManual testing258260--0.054--
2009-01-04T11:07:00Sturle Sundeagrell.ifi260261--0.072--
2012-04-03T08:47:00Sebastian HornbostelManual testing261262--0.145--
2013-09-06T08:32:00ramgeisManual testing262263--0.462--
2015-03-15T12:13:00VictordeHollanderManual testing263264--0.924--
2015-03-15T12:13:00VictordeHollanderManual testing264265--1.758--
2016-01-06T22:34:26ramgeisManual testing265266--3.515--
2016-10-15T17:13:26Gordon SpenceManual testing266267--7.031--
2019-05-06T12:23:35TJAOIManual testing267268--14.06--


ECM factoring results:

Old Calculation Method

Total ECM effort:13.456 GHz-days
Estimated T-Level:22.786
DigitsB1CurvesCompleteFacMiss
2011000156 / 1001.56020.849%
2550000156 / 2800.55757.227%

New Calculation Method

Total ECM effort:13.456 GHz-days
Estimated T-Level:22.786
DigitsB1CompleteFacMiss
20110005.0560.637%
25500000.45863.253%
302500000.02897.211%
3510000000.00199.870%


ECM Summary

B1B2factorcurvesGHz-days
50000500000014912.70
50000500000060.511
766202417689010.246


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-06-15T00:00:00ANONYMOUSv4_computers076A89FDEE37EA470.140
2018-04-05T02:06:59kkmrkkblmbrbkold076A89FDEE37EA470.140


PRP results:
dateuseridcompidcofactorsres64PRP
2021-03-22T14:00:39mrhlanai
427461968542411008522807721
3DC77C24A34E1767no


P-1 factor-bounds graph:
B1 = 2500000, B2 = 125000000 (P-1 stage 2)
B1 = 2500000 (P-1 stage 1)
B1 = 504000, B2 = 5040000 (P-1 stage 2)
B1 = 420000, B2 = 4200000 (P-1 stage 2)
B1 = 210000, B2 = 6090000 (P-1 stage 2)
B1 = 504000 (P-1 stage 1)
B1 = 420000 (P-1 stage 1)
B1 = 140000, B2 = 3045000 (P-1 stage 2)
B1 = 210000 (P-1 stage 1)
B1 = 140000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 20000, B2 = 265000 (P-1 stage 2)
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: 2021-03-22T14:00:39+00:00