is 2 2127751 - 1
has 640517 decimal digits
takes 0.140 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L2D35F288433BA5D2double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26956.109468.1159%25000001250000000.87467.2833%56.984070.4381%2.3222%
PrimeNet2580.018062.0690%90001600000.00162.6844%0.019763.0872%1.0182%
GPU722620.288764.5161%100001400000.00161.4552%0.290465.0325%0.5164%
Difference+7+55.8206+3.5998%+2490000+124860000+0.8730+5.8281%+56.6937+5.4057%+5.4057%

Known prime factors:
No known factors for M2127751

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-08-08T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.180%
2009-08-03T23:22:00harleeP4_260020000265000---0.003--0.759%
2011-01-01T00:57:00Jocelyn LaroucheManual testing3000030000---0.003--0.298%
2011-01-12T23:59:00Jocelyn LaroucheManual testing5000050000---0.005--0.437%
2011-01-25T16:23:00James Heinrichi7-9201400003045000---0.028--2.477%
2016-06-28T05:38:31Jocelyn LaroucheManual testing210000609000012---0.051--3.108%
2017-08-19T15:19:15Jocelyn Larouchelow 4M42000042000006---0.060--3.164%
2017-08-30T00:32:09Jocelyn Larouchelow 4M50400050400006---0.072--3.374%
2017-09-14T19:10:21mikrMSI250000012500000012---0.875--7.283%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-01-29T00:00:00ANONYMOUSv4_computers21258--0.018--
2016-02-23T16:29:05Mark RoseManual testing258260--0.054--
2009-01-04T17:17:00Sturle Sundebuxtehude.ifi260261--0.072--
2012-04-04T03:48:00Sebastian HornbostelManual testing261262--0.144--
2013-09-06T08:32:00ramgeisManual testing262263--0.461--
2015-03-15T12:13:00VictordeHollanderManual testing263264--0.923--
2015-03-15T12:13:00VictordeHollanderManual testing264265--1.756--
2015-12-27T16:49:11ramgeisManual testing265266--3.512--
2016-10-15T17:13:27Gordon SpenceManual testing266267--7.024--
2019-04-29T13:20:35TJAOIManual testing267268--14.05--
2021-08-12T13:16:27TJAOIManual testing268269--28.10--


ECM factoring results:

Old Calculation Method

Total ECM effort:17.208 GHz-days
Estimated T-Level:23.554
DigitsB1CurvesCompleteFacMiss
2011000199 / 1001.99013.533%
2550000199 / 2800.71149.067%

New Calculation Method

Total ECM effort:17.208 GHz-days
Estimated T-Level:23.554
DigitsB1CompleteFacMiss
20110007.7040.045%
25500000.71448.969%
302500000.04595.585%
3510000000.00299.789%


ECM Summary

B1B2factorcurvesGHz-days
50000500000019116.28
50000675000070.682
766202417689010.246


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-29T00:00:00ANONYMOUSv4_computers2D35F288433BA5D20.140
2018-04-05T09:54:31kkmrkkblmbrbkold2D35F288433BA5D20.140


PRP results:
No PRP results for M2127751


P-1 factor-bounds graph:
B1 = 2500000, B2 = 125000000 (P-1 stage 2)
B1 = 2500000 (P-1 stage 1)
B1 = 504000, B2 = 5040000 (P-1 stage 2)
B1 = 420000, B2 = 4200000 (P-1 stage 2)
B1 = 210000, B2 = 6090000 (P-1 stage 2)
B1 = 504000 (P-1 stage 1)
B1 = 420000 (P-1 stage 1)
B1 = 140000, B2 = 3045000 (P-1 stage 2)
B1 = 210000 (P-1 stage 1)
B1 = 140000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 20000, B2 = 265000 (P-1 stage 2)
B1 = 30000 (P-1 stage 1)
B1 = 20000 (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: 2021-12-27T09:25:30+00:00