is 2 2783959 - 1
has 838056 decimal digits
takes 0.215 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LBE2247B6670E3663double-checked
PRP3C21C67EECB86F6Cverified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26942.883868.1159%3000000900000000.86687.2152%43.750670.4164%2.3005%
PrimeNet2590.027662.7119%120002200000.00262.8588%0.030263.7779%1.0660%
GPU722630.573365.0794%150002400000.00311.7479%0.576365.6898%0.6104%
Difference+6+42.3105+3.0366%+2985000+89760000+0.8638+5.4673%+43.1743+4.7267%+4.7267%

Known prime factors (1 factor, 72.5 bits, 0.00260532% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
278395968242851471430532672812272.5311225643974487960
23 × 5 × 22441 × 1365407039		2021-07-23224411365407039626.118.333615.560

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-17T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.195%
2010-11-11T04:19:00Jocelyn LaroucheManual testing1500015000---0.002--0.175%
2010-11-25T16:54:00markrtiny1000002075000---0.023--2.203%
2014-10-28T23:25:00Jocelyn LaroucheManual testing123055123055---0.014--0.823%
2016-05-03T01:41:41Jocelyn LaroucheManual testing20000036000006---0.043--2.851%
2017-07-20T22:03:20Jocelyn Larouchelow 4M40000040000006---0.067--3.221%
2019-11-15T08:28:13BigBrotherWinston30000009000000012---0.867--7.215%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:21Mark RoseManual testing21260--0.055--
2009-01-28T16:44:00Sturle Sundegimba.ifi260261--0.055--
2012-04-04T04:44:00Grant McCrackenhome261262--0.110--
2013-01-14T12:31:00dbaughManual testing262263--0.353--
2015-04-21T09:20:00VictordeHollanderManual testing263264--0.705--
2015-04-21T09:20:00VictordeHollanderManual testing264265--1.342--
2016-02-08T11:13:52ramgeisManual testing265266--2.684--
2017-10-16T21:21:14Gordon SpenceManual testing266267--5.368--
2019-02-25T02:38:33chuenkitManual testing267268--10.74--
2021-07-08T15:44:07TJAOIManual testing268269--21.47--


ECM factoring results:

Old Calculation Method

Total ECM effort:10.330 GHz-days
Estimated T-Level:4.850
DigitsB1CurvesCompleteFacMiss
201100097 / 1000.97037.724%
255000097 / 2800.34670.677%

New Calculation Method

Total ECM effort:10.330 GHz-days
Estimated T-Level:4.850
DigitsB1CompleteFacMiss
20110003.7792.285%
25500000.34970.507%
302500000.02297.816%
3510000000.00199.897%


ECM Summary

B1B2factorcurvesGHz-days
500005000000828.535
50000645000010.117
500006750000141.677


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-06-26T00:00:00ANONYMOUSv4_computersBE2247B6670E36630.215
2018-08-26T11:25:37kkmrkkblmbrbkoldBE2247B6670E36630.215


PRP results:
dateuseridcompidcofactorsres64PRP
2021-07-24T08:35:15kutenssol
6824285147143053267281
3C21C67EECB86F6Cno


P-1 factor-bounds graph:
B1 = 3000000, B2 = 90000000 (P-1 stage 2)
B1 = 3000000 (P-1 stage 1)
B1 = 400000, B2 = 4000000 (P-1 stage 2)
B1 = 400000 (P-1 stage 1)
B1 = 200000, B2 = 3600000 (P-1 stage 2)
B1 = 100000, B2 = 2075000 (P-1 stage 2)
B1 = 200000 (P-1 stage 1)
B1 = 123055 (P-1 stage 1)
B1 = 100000 (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: 2021-07-24T08:35:15+00:00