is 2 2020661 - 1
has 608280 decimal digits
takes 0.133 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L977603765C5A01F6double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26829.497769.1176%40000002000000001.39948.7489%30.897171.8195%2.7019%
PrimeNet2580.019063.7931%90001500000.00162.6121%0.020664.7389%0.9458%
GPU722620.304066.1290%80001200000.00131.2734%0.305466.5603%0.4313%
Difference+6+29.1937+2.9886%+3992000+199880000+1.3981+7.4755%+30.5918+5.2592%+5.2592%

Known prime factors (1 factor, 89.9 bits, 0.00444762% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
202066111323389498338076933972595032889.871280190232264048173691
3 × 13 × 409 × 17565684425054741
2020-02-2940917565684425054741123,163,21491,240,556170,411,950

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-04-28T00:00:00Jocelyn Larouchev4_computers20002000---0.000--0.017%
2002-12-31T00:00:00ANONYMOUSv4_computers25000412500---0.004--1.078%
2010-12-08T22:41:00Jocelyn LaroucheManual testing202066202066---0.019--1.170%
2013-10-18T06:05:00David Campeaui5-2500k58000015080000---0.131--4.745%
2019-02-25T12:57:37mikrMSI400000020000000012---1.399--8.749%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-26T00:00:00ANONYMOUSv4_computers21258--0.019--
2016-02-23T16:29:03Mark RoseManual testing258260--0.057--
2009-01-02T10:33:00Sturle Sundefizir.ifi260261--0.076--
2012-02-04T16:48:00Sebastian HornbostelManual testing261262--0.152--
2013-02-11T20:23:00dbaughManual testing262263--0.486--
2015-04-10T15:56:00VictordeHollanderManual testing263264--0.972--
2015-04-10T15:56:00VictordeHollanderManual testing264265--1.849--
2015-10-28T09:42:37ramgeisManual testing265266--3.698--
2016-07-02T13:21:34Gordon SpenceManual testing266267--7.396--
2019-03-18T03:51:00chuenkitManual testing267268--14.79--


ECM factoring results:

Old Calculation Method

Total ECM effort:6.521 GHz-days
Estimated T-Level:3.850
DigitsB1CurvesCompleteFacMiss
201100077 / 1000.77046.122%
255000077 / 2800.27575.920%

New Calculation Method

Total ECM effort:6.521 GHz-days
Estimated T-Level:3.850
DigitsB1CompleteFacMiss
20110002.4848.342%
25500000.22479.892%
302500000.01498.627%


ECM Summary

B1B2factorcurvesGHz-days
500005000000756.352
50000500000020.169


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-13T00:00:00ANONYMOUSv4_computers977603765C5A01F60.133
2016-07-15T13:25:59Mark Rosemichelangelo977603765C5A01F60.133


PRP results:
dateuseridcompidcofactorsres64PRP
2020-03-01T12:25:18Christoph ZengerManual testing
1132338949833807693397259503
2CB145E40B6A8506no
2020-03-03T19:02:53Bommer2600X
1132338949833807693397259503
2CB145E40B6A8506no


P-1 factor-bounds graph:
B1 = 4000000, B2 = 200000000 (P-1 stage 2)
B1 = 4000000 (P-1 stage 1)
B1 = 580000, B2 = 15080000 (P-1 stage 2)
B1 = 580000 (P-1 stage 1)
B1 = 202066 (P-1 stage 1)
B1 = 25000, B2 = 412500 (P-1 stage 2)
B1 = 25000 (P-1 stage 1)
B1 = 2000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-03-03T19:02:53+00:00