is 2 4871981 - 1
has 1466613 decimal digits
takes 0.675 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L893A84C93320AE32double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual272196.292668.0556%29150001107700001.76696.1403%198.059570.0170%1.9615%
PrimeNet2610.063162.2951%220004500000.00913.2990%0.072263.5390%1.2439%
GPU722651.497564.6154%320007000000.01372.3717%1.511265.4546%0.8392%
Difference+7+194.7951+3.4402%+2883000+110070000+1.7532+3.7686%+196.5483+4.5624%+4.5624%

Known prime factors:
No known factors for M4871981

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2009-08-17T07:51:00Carsten Kossendeydurandal30000435000---0.010--0.766%
2013-12-20T02:01:00David Campeaui5-2500k42000010920000---0.199--3.195%
2013-12-28T03:37:00David Campeaui5-2500k2915000110770000---1.767--6.140%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:39:03Mark RoseManual testing21261--0.063--
2010-04-20T10:02:00markroldgamer261262--0.063--
2011-10-09T22:43:00GrunwalderGIMPManual testing21263--0.328--
2016-02-23T16:39:03Mark RoseManual testing262263--0.201--
2015-01-09T11:16:00VictordeHollanderManual testing263264--0.403--
2015-01-09T11:16:00VictordeHollanderManual testing264265--0.767--
2015-07-21T21:29:00snme2pm1Manual testing265266--1.534--
2017-11-05T12:03:39YxinityManual testing266267--3.068--
2018-05-08T11:46:37ramgeisManual testing267268--6.135--
2018-07-22T12:21:48YxinityManual testing268269--12.27--
2018-07-22T12:21:48YxinityManual testing269270--24.54--
2020-12-04T00:54:02-Anonymous-Manual testing270271--49.08--
2020-12-06T19:22:42-Anonymous-Manual testing271272--98.16--


ECM factoring results:

Old Calculation Method

Total ECM effort:1.885 GHz-days
Estimated T-Level:0.450
DigitsB1CurvesCompleteFacMiss
20110009 / 1000.09091.352%
25500009 / 2800.03296.831%

New Calculation Method

Total ECM effort:1.885 GHz-days
Estimated T-Level:0.450
DigitsB1CompleteFacMiss
20110000.34670.740%
25500000.03296.848%
302500000.00299.798%


ECM Summary

B1B2factorcurvesGHz-days
50000500000091.885


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-05-08T00:00:00ANONYMOUSv4_computers893A84C93320AE320.675
1998-08-02T00:00:00ANONYMOUSv4_computers893A84C93320AE320.675
2000-03-15T00:00:00ANONYMOUSv4_computers893A84C93320AE320.675


PRP results:
No PRP results for M4871981


P-1 factor-bounds graph:
B1 = 2915000, B2 = 110770000 (P-1 stage 2)
B1 = 2915000 (P-1 stage 1)
B1 = 420000, B2 = 10920000 (P-1 stage 2)
B1 = 420000 (P-1 stage 1)
B1 = 30000, B2 = 435000 (P-1 stage 2)
B1 = 30000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-12-06T19:22:42+00:00