is 2 1622879 - 1
has 488536 decimal digits
takes 0.072 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L3152D0416DEB3BBFdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26836.727969.1176%100000002000000001.31819.0706%38.046071.9188%2.8012%
PrimeNet2570.011863.1579%70001200000.00092.5552%0.012764.0993%0.9414%
GPU722610.189365.5738%6500600000.00061.0597%0.189965.9386%0.3648%
Difference+7+36.5386+3.5439%+9993500+199940000+1.3175+8.0109%+37.8561+5.9803%+5.9803%

Known prime factors:
No known factors for M1622879

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2011-12-01T12:37:00BigBrotherWinston100000020000000---0.132--5.177%
2016-12-08T17:16:00Jocelyn Larouchelow 4M16228791622879---0.105--2.781%
2017-07-18T02:33:42Jocelyn Larouchelow 4M20674542067454012---0.200--5.542%
2018-02-08T12:52:28Jocelyn Larouchelow 4M20674544134908012---0.273--6.316%
2018-02-22T12:45:31Jocelyn Larouchelow 4M20674548269816012---0.418--7.099%
2018-02-24T23:22:00VictordeHollanderManual testing1000000020000000012---1.318--9.071%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-06-05T10:29:03Team_InspectorPurple10000005000000027--0.268


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-11-07T00:00:00ANONYMOUSv4_computers21257--0.012--
2003-07-06T00:00:00ANONYMOUSv4_computers21258--0.024--
2016-02-23T16:28:41Mark RoseManual testing258260--0.071--
2010-05-05T12:20:00Architects Cubeda3_lm260261--0.095--
2016-02-23T16:28:41Mark RoseManual testing261262--0.189--
2010-08-13T02:23:00GrunwalderGIMPManual testing21263--0.983--
2016-02-23T16:28:41Mark RoseManual testing262263--0.605--
2015-04-29T10:57:00omylistManual testing263264--1.210--
2015-04-30T14:35:00monstManual testing264265--2.302--
2015-10-11T16:52:29ramgeisManual testing265266--4.605--
2017-11-17T15:40:10TJAOIManual testing266267--9.209--
2019-08-06T10:06:05TJAOIManual testing267268--18.42--


ECM factoring results:

Old Calculation Method

Total ECM effort:15.721 GHz-days
Estimated T-Level:25.000
DigitsB1CurvesCompleteFacMiss
2011000280 / 1002.8005.996%
2550000280 / 2801.00036.722%

New Calculation Method

Total ECM effort:15.721 GHz-days
DigitsB1CompleteFacMiss
201100010.7690.002%
25500000.99636.919%
302500000.06393.908%
3510000000.00399.707%


ECM Summary

B1B2factorcurvesGHz-days
50000500000028015.72


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-11-07T00:00:00ANONYMOUSv4_computers3152D0416DEB3BBF0.072
2015-07-19T18:02:00MadPooManual testing3152D0416DEB3BBF0.072


PRP results:
No PRP results for M1622879


P-1 factor-bounds graph:
B1 = 10000000, B2 = 200000000 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
B1 = 2067454, B2 = 82698160 (P-1 stage 2)
B1 = 2067454, B2 = 41349080 (P-1 stage 2)
B1 = 2067454, B2 = 20674540 (P-1 stage 2)
B1 = 2067454 (P-1 stage 1)
B1 = 1000000, B2 = 20000000 (P-1 stage 2)
B1 = 1622879 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2021-06-05T10:29:03+00:00