is 2 2488121 - 1
has 749000 decimal digits
takes 0.173 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LC458B67B572081E2double-checked
PRP886D20A7F95A6369verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26947.982768.1159%2382500857701000.69656.9451%48.679370.3303%2.2144%
PrimeNet2590.030962.7119%100001800000.00192.5356%0.032863.6573%0.9455%
GPU722630.641565.0794%110001600000.00191.3807%0.643465.5615%0.4822%
Difference+6+47.3413+3.0366%+2371500+85610100+0.6946+5.5644%+48.0359+4.7688%+4.7688%

Known prime factors (1 factor, 74.2 bits, 0.00298162% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2488121214931278810315122794392374.1864319148441943039
224351 × 19251745889
2021-11-03224351192517458891,823.6105.51197.03

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-14T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.189%
2003-10-31T00:00:00Team Prime Ribv4_computers15000228750---0.003--0.671%
2010-12-22T11:37:00Jocelyn LaroucheManual testing2000020000---0.002--0.221%
2011-01-21T05:18:00Oscar Östlin950001947500---0.020--2.108%
2014-09-03T20:52:00Jocelyn LaroucheManual testing120796120796---0.012--0.797%
2014-11-20T14:31:00mikrMSI238250085770100---0.697--6.945%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-05-02T00:00:00ANONYMOUSv4_computers21259--0.031--
2016-02-23T16:29:15Mark RoseManual testing259260--0.031--
2009-01-14T21:11:00Sturle Sundegiovanni.ifi260261--0.062--
2012-06-10T14:43:00Sebastian HornbostelManual testing261262--0.123--
2013-12-04T21:13:00Jerry HallettManual testing262263--0.395--
2015-03-03T21:37:00VictordeHollanderManual testing263264--0.789--
2015-03-03T21:37:00VictordeHollanderManual testing264265--1.502--
2015-10-30T09:42:35ramgeisManual testing265266--3.003--
2017-07-24T22:21:27Gordon SpenceManual testing266267--6.007--
2019-05-20T13:24:26TJAOIManual testing267268--12.01--
2021-06-10T09:21:43TJAOIManual testing268269--24.03--


ECM factoring results:

Old Calculation Method

Total ECM effort:13.421 GHz-days
Estimated T-Level:22.607
DigitsB1CurvesCompleteFacMiss
2011000146 / 1001.46023.054%
2550000146 / 2800.52159.312%

New Calculation Method

Total ECM effort:13.421 GHz-days
Estimated T-Level:22.607
DigitsB1CompleteFacMiss
20110004.7170.894%
25500000.42665.326%
302500000.02697.412%
3510000000.00199.880%


ECM Summary

B1B2factorcurvesGHz-days
50000500000013612.49
50000500000030.276
50000515000070.651


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-16T00:00:00ANONYMOUSv4_computersC458B67B572081E20.173
2018-05-31T13:22:05kkmrkkblmbrbkoldC458B67B572081E20.173


PRP results:
dateuseridcompidcofactorsres64PRP
2021-11-04T10:15:12SRJ2877LTOS
21493127881031512279439
886D20A7F95A6369no


P-1 factor-bounds graph:
B1 = 2382500, B2 = 85770100 (P-1 stage 2)
B1 = 2382500 (P-1 stage 1)
B1 = 95000, B2 = 1947500 (P-1 stage 2)
B1 = 120796 (P-1 stage 1)
B1 = 95000 (P-1 stage 1)
B1 = 15000, B2 = 228750 (P-1 stage 2)
B1 = 20000 (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: 2021-11-04T10:15:12+00:00