is 2 1647853 - 1
has 496054 decimal digits
takes 0.074 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L467E06F1AF42A3D9double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26836.171269.1176%20000001812638300.76217.9813%36.933371.5825%2.4648%
PrimeNet2570.011763.1579%70001200000.00092.5628%0.012564.1021%0.9442%
GPU722610.186465.5738%6500800000.00071.1718%0.187165.9772%0.4034%
Difference+7+35.9848+3.5439%+1993500+181183830+0.7614+6.8096%+36.7462+5.6053%+5.6053%

Known prime factors:
No known factors for M1647853

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2012-02-29T17:07:00AxonManual testing100000100000---0.006--0.761%
2012-02-29T17:12:00AxonManual testing200000200000---0.013--1.124%
2012-02-29T18:07:00AxonManual testing300000300000---0.019--1.379%
2012-02-29T18:11:00AxonManual testing400000400000---0.026--1.579%
2012-02-29T19:09:00AxonManual testing500000500000---0.032--1.746%
2012-02-29T19:12:00AxonManual testing600000600000---0.039--1.889%
2012-02-29T20:08:00AxonManual testing700000700000---0.045--2.015%
2012-02-29T20:11:00AxonManual testing800000800000---0.052--2.128%
2012-02-29T21:09:00AxonManual testing900000900000---0.058--2.231%
2012-02-29T21:13:00AxonManual testing10000001000000---0.065--2.325%
2012-03-01T06:07:00AxonManual testing10000008000000---0.089--4.291%
2012-03-01T07:08:00AxonManual testing100000020000000---0.132--5.186%
2017-09-01T01:41:28Jocelyn Larouchelow 4M20000002000000012---0.193--5.502%
2018-02-08T12:52:25Jocelyn Larouchelow 4M20000004000000012---0.264--6.272%
2018-02-19T11:48:46Jocelyn Larouchelow 4M20000008000000012---0.405--7.052%
2018-09-24T11:55:51Jocelyn Larouchelow 4M200000016478530012---0.704--7.873%
2018-10-16T11:47:45Jocelyn Larouchelow 4M200000018126383012---0.762--7.981%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-04-02T00:00:00ANONYMOUSv4_computers21257--0.012--
2003-05-19T00:00:00ANONYMOUSv4_computers21258--0.023--
2016-02-23T16:28:44Mark RoseManual testing258260--0.070--
2010-04-30T08:40:00Architects Cubedm1_76l260261--0.093--
2016-02-23T16:28:44Mark RoseManual testing261262--0.186--
2010-08-03T22:36:00GrunwalderGIMPManual testing21263--0.969--
2016-02-23T16:28:44Mark RoseManual testing262263--0.596--
2015-05-06T17:29:00omylistManual testing263264--1.191--
2015-05-07T09:32:00monstManual testing264265--2.267--
2015-10-11T16:52:32ramgeisManual testing265266--4.535--
2017-10-27T12:33:03TJAOIManual testing266267--9.070--
2019-07-31T09:42:10TJAOIManual testing267268--18.14--


ECM factoring results:

Old Calculation Method

Total ECM effort:15.745 GHz-days
Estimated T-Level:25.000
DigitsB1CurvesCompleteFacMiss
2011000280 / 1002.8005.996%
2550000280 / 2801.00036.722%

New Calculation Method

Total ECM effort:15.745 GHz-days
Estimated T-Level:25.000
DigitsB1CompleteFacMiss
201100010.7690.002%
25500000.99636.919%
302500000.06393.908%
3510000000.00399.707%


ECM Summary

B1B2factorcurvesGHz-days
50000500000028015.75


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-13T00:00:00ANONYMOUSv4_computers467E06F1AF42A3D90.074
2015-06-28T05:06:00MadPooManual testing467E06F1AF42A3D90.074


PRP results:
No PRP results for M1647853


P-1 factor-bounds graph:
B1 = 2000000, B2 = 181263830 (P-1 stage 2)
B1 = 2000000, B2 = 164785300 (P-1 stage 2)
B1 = 2000000, B2 = 80000000 (P-1 stage 2)
B1 = 2000000, B2 = 40000000 (P-1 stage 2)
B1 = 2000000, B2 = 20000000 (P-1 stage 2)
B1 = 1000000, B2 = 20000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 1000000, B2 = 8000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 900000 (P-1 stage 1)
B1 = 800000 (P-1 stage 1)
B1 = 700000 (P-1 stage 1)
B1 = 600000 (P-1 stage 1)
B1 = 500000 (P-1 stage 1)
B1 = 400000 (P-1 stage 1)
B1 = 300000 (P-1 stage 1)
B1 = 200000 (P-1 stage 1)
B1 = 100000 (P-1 stage 1)
104
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107
104
105
106
107
108
109
TF factor-bounds graph:
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Last modified: 2019-07-31T09:42:10+00:00