is 2 2915491 - 1
has 877651 decimal digits
takes 0.225 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L538408CB78DE20DFdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26940.949168.1159%50000002000000001.74988.5132%42.698970.8303%2.7144%
PrimeNet2590.026362.7119%130002600000.00303.0672%0.029363.8556%1.1437%
GPU722630.547465.0794%160003000000.00351.9109%0.551065.7467%0.6673%
Difference+6+40.4017+3.0366%+4984000+199700000+1.7463+6.6023%+42.1480+5.0836%+5.0836%

Known prime factors:
No known factors for M2915491

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-12-02T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.198%
2009-07-03T00:46:00Carsten Kossendeyleela15000168750---0.003--0.628%
2010-12-24T02:50:00Jocelyn LaroucheManual testing2000020000---0.002--0.229%
2011-01-25T19:27:00markrtiny1050002283750---0.025--2.293%
2015-04-25T17:20:00VictordeHollanderManual testing100000020000000---0.228--5.049%
2020-03-30T16:31:03masserManual testing500000020000000012---1.750--8.513%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-05-23T00:00:00BJBv4_computers21259--0.026--
2016-02-23T16:29:24Mark RoseManual testing259260--0.026--
2009-02-12T22:59:00Sturle Sundekrebs.ifi260261--0.053--
2011-12-20T18:37:00Grant McCrackenthumper261262--0.105--
2013-01-10T21:10:00dbaughManual testing262263--0.337--
2015-04-25T17:15:00VictordeHollanderManual testing263264--0.673--
2015-04-25T17:15:00VictordeHollanderManual testing264265--1.282--
2016-02-22T09:35:53ramgeisManual testing265266--2.563--
2017-11-19T23:57:51Gordon SpenceManual testing266267--5.126--
2018-12-18T01:52:41chuenkitManual testing267268--10.25--
2021-05-31T09:33:25TJAOIManual testing268269--20.50--


ECM factoring results:

Old Calculation Method

Total ECM effort:12.385 GHz-days
Estimated T-Level:22.071
DigitsB1CurvesCompleteFacMiss
2011000116 / 1001.16031.166%
2550000116 / 2800.41466.032%

New Calculation Method

Total ECM effort:12.385 GHz-days
Estimated T-Level:22.071
DigitsB1CompleteFacMiss
20110004.5061.104%
25500000.41765.919%
302500000.02697.403%
3510000000.00199.877%


ECM Summary

B1B2factorcurvesGHz-days
50000500000010210.70
50000645000070.827
50000696378570.860


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-09-06T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
1999-05-02T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-02-09T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-04-12T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-04-27T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-05-05T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-07-12T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-08-17T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-08-31T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-09-08T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225
2000-09-29T00:00:00ANONYMOUSv4_computers538408CB78DE20DF0.225


PRP results:
No PRP results for M2915491


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 1000000, B2 = 20000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 105000, B2 = 2283750 (P-1 stage 2)
B1 = 105000 (P-1 stage 1)
B1 = 15000, B2 = 168750 (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: 2022-06-07T20:23:37+00:00