is 2 2198747 - 1
has 661889 decimal digits
takes 0.145 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L9A97D12509BE731Adouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26827.108667.6471%25000001250000000.87467.9346%27.983270.2141%2.5671%
PrimeNet2580.017562.0690%100001800000.00182.8628%0.019363.1548%1.0859%
GPU722620.279464.5161%110001700000.00191.5998%0.281365.0838%0.5677%
Difference+6+26.8292+3.1309%+2489000+124830000+0.8728+6.3348%+27.7019+5.1303%+5.1303%

Known prime factors (1 factor, 80.6 bits, 0.00366692% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
219874718660217362612694200451672580.626424337528660930389
29 × 1723 × 55381 × 153344207
2020-05-1055381153344207145,8130.80151.4877

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-03-16T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.226%
2010-11-05T01:17:00Jocelyn LaroucheManual testing1500015000---0.001--0.199%
2010-11-09T10:51:00Jocelyn LaroucheManual testing3000030000---0.003--0.355%
2011-01-10T19:10:00markrtiny900001620000---0.017--2.207%
2014-07-04T02:21:00Jocelyn LaroucheManual testing119191119191---0.011--0.890%
2014-10-13T22:29:00Jocelyn LaroucheManual testing148382148382---0.014--1.007%
2016-02-05T12:25:21Jocelyn LaroucheManual testing58320058320006---0.083--3.939%
2018-03-27T19:29:55mikrMSI250000012500000012---0.875--7.935%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-02-07T00:00:00ANONYMOUSv4_computers21258--0.017--
2016-02-23T16:29:08Mark RoseManual testing258260--0.052--
2009-01-03T02:27:00Sturle Sundegibsy.ifi260261--0.070--
2009-01-08T00:01:00Sturle Sundegnom.ifi261262--0.140--
2013-01-23T08:20:00dbaughManual testing262263--0.446--
2015-03-28T18:03:00VictordeHollanderManual testing263264--0.893--
2015-03-28T18:03:00VictordeHollanderManual testing264265--1.699--
2016-01-07T16:51:52ramgeisManual testing265266--3.399--
2016-12-03T03:08:56Gordon SpenceManual testing266267--6.797--
2019-04-01T13:34:48TJAOIManual testing267268--13.59--


ECM factoring results:

Old Calculation Method

Total ECM effort:6.420 GHz-days
Estimated T-Level:3.750
DigitsB1CurvesCompleteFacMiss
201100075 / 1000.75047.059%
255000075 / 2800.26876.465%

New Calculation Method

Total ECM effort:6.420 GHz-days
Estimated T-Level:3.750
DigitsB1CompleteFacMiss
20110002.4198.898%
25500000.21980.360%
302500000.01398.663%


ECM Summary

B1B2factorcurvesGHz-days
500005000000726.163
50000500000030.257


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-01T00:00:00ANONYMOUSv4_computers9A97D12509BE731A0.145
2018-04-15T21:16:57kkmrkkblmbrbkold9A97D12509BE731A0.145


PRP results:
dateuseridcompidcofactorsres64PRP
2020-05-11T07:46:56Christoph ZengerManual testing
1866021736261269420045167
9AA740A6F56953A1no
2020-05-13T06:10:49ANONYMOUSobFIV_MkQmyMzMWzFMY2
1866021736261269420045167
9AA740A6F56953A1no


P-1 factor-bounds graph:
B1 = 2500000, B2 = 125000000 (P-1 stage 2)
B1 = 2500000 (P-1 stage 1)
B1 = 583200, B2 = 5832000 (P-1 stage 2)
B1 = 583200 (P-1 stage 1)
B1 = 90000, B2 = 1620000 (P-1 stage 2)
B1 = 148382 (P-1 stage 1)
B1 = 119191 (P-1 stage 1)
B1 = 90000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000 (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: 2020-05-13T06:10:49+00:00