is 2 2892781 - 1
has 870814 decimal digits
takes 0.223 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L931B77CB499C0BC8double-checked
PRP181BE80CCC6B8519verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26820.604767.6471%50000002000000001.74989.1859%22.354570.6190%2.9719%
PrimeNet2590.026562.7119%130002400000.00283.0008%0.029463.8308%1.1189%
GPU722630.551765.0794%160003000000.00351.9081%0.555265.7457%0.6663%
Difference+5+20.0530+2.5677%+4984000+199700000+1.7463+7.2778%+21.7992+4.8733%+4.8733%

Known prime factors (1 factor, 68.4 bits, 0.00236344% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28927813812290365171329308732168.36965893172783756
22 × 107 × 353 × 436136009
2020-12-3135343613600933.7382.66124.9703

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-12-02T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.245%
2016-10-27T15:25:31Jocelyn Larouchelow 4M172800172800---0.019--1.146%
2016-12-14T18:29:39Jocelyn Larouchelow 4M248832248832---0.028--1.380%
2017-02-25T21:08:08Jocelyn Larouchelow 4M29859829859806---0.050--3.238%
2017-10-21T00:17:08Jocelyn Larouchelow 4M59719659719606---0.100--4.108%
2019-10-23T17:07:32masserManual testing29000002900000012---0.484--6.444%
2020-02-11T03:26:38masserManual testing500000020000000012---1.750--9.186%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:24Mark RoseManual testing21260--0.053--
2009-02-13T00:50:00Sturle Sundegehry.ifi260261--0.053--
2012-01-14T12:18:00markroldgamer261262--0.106--
2013-01-10T10:24:00dbaughManual testing262263--0.339--
2015-04-21T09:21:00VictordeHollanderManual testing263264--0.679--
2015-04-21T09:21:00VictordeHollanderManual testing264265--1.292--
2015-11-28T11:39:32omylistManual testing265266--2.583--
2017-11-16T23:15:00Gordon SpenceManual testing266267--5.166--
2019-01-12T08:34:57chuenkitManual testing267268--10.33--


ECM factoring results:

Old Calculation Method

Total ECM effort:6.285 GHz-days
Estimated T-Level:3.000
DigitsB1CurvesCompleteFacMiss
201100060 / 1000.60054.716%
255000060 / 2800.21480.681%

New Calculation Method

Total ECM effort:6.285 GHz-days
Estimated T-Level:3.000
DigitsB1CompleteFacMiss
20110001.93514.435%
25500000.17583.952%
302500000.01198.929%


ECM Summary

B1B2factorcurvesGHz-days
500005000000495.132
500005000000111.152


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2000-02-01T00:00:00ANONYMOUSv4_computers931B77CB499C0BC80.223
2018-09-28T03:36:38kkmrkkblmbrbkold931B77CB499C0BC80.223


PRP results:
dateuseridcompidcofactorsres64PRP
2021-01-01T17:23:08Niels_Mache_Nextcloudconf4-a
381229036517132930873
181BE80CCC6B8519no


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 2900000, B2 = 29000000 (P-1 stage 2)
B1 = 2900000 (P-1 stage 1)
B1 = 597196, B2 = 5971960 (P-1 stage 2)
B1 = 597196 (P-1 stage 1)
B1 = 298598, B2 = 2985980 (P-1 stage 2)
B1 = 298598 (P-1 stage 1)
B1 = 248832 (P-1 stage 1)
B1 = 172800 (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: 2021-01-01T17:23:08+00:00