is 2 12281 - 1
has 3697 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LF39F1808E5C18969double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual2672,419.503179.1045 %1000000000000140016017331290100021,815,543.758645.6061 %21,817,963.261788.6341 %
Target2440.000268.1818 %500500000.00001.3458 %0.000268.6100 %
Difference+23+2,419.5029+10.9227 %+999999999500+1400160173312851000+21,815,543.7586+44.2603%+21,817,963.2616+20.0241 %

Known prime factors:
No known factors for M12281

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2001-04-29ANONYMOUSv4_computers10000010000000--0.00019.195%
2001-07-17Alex Kruppav4_computers1000000100000000--0.00227.203%
2001-09-22ANONYMOUSv4_computers430000004290000000--0.07839.195%
2002-04-28ANONYMOUSv4_computers163841638400--3.00000e-512.728%
2002-06-09ANONYMOUSv4_computers327683276800--5.99000e-515.213%
2002-07-14ANONYMOUSv4_computers65536655360012--0.00017.691%
2003-02-02ANONYMOUSv4_computers1310721310720030--0.00020.154%
2003-03-27ANONYMOUSv4_computers2621442621440030--0.00022.591%
2003-04-03ANONYMOUSv4_computers5242885242880048--0.00124.997%
2003-04-27ANONYMOUSv4_computers104857610485760048--0.00227.363%
2003-05-19ANONYMOUSv4_computers209715220971520012--0.00429.685%
2003-07-06ANONYMOUSv4_computers419430441943040012--0.00831.959%
2003-09-29ANONYMOUSv4_computers16777216167772160012--0.03136.348%
2003-09-29ANONYMOUSv4_computers838860883886080012--0.01534.181%
2011-05-06ANONYMOUSManual testing10000000001000000000--0.28632.882%
2013-01-29bcp19Toshiba-740Q1000000000010000000000012--4.26246.279%
2018-07-03James Hintz3_1_201825971532008194786490060012--37.3754.456%
2022-03-14ANONYMOUST5810100000000000121047848166084840--500,00079.212%
2022-10-29ANONYMOUST581010000000000001400160173312901000--500,00083.250%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-05-09ATH5960X100000000024100000000027--4.099
2023-07-09masserManual testing6500000002600000000011011--0.670
2023-08-24masserManual testing65000000011635000000065--2.049


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1999-09-14ANONYMOUSv4_computers2522530.049
2000-01-19ANONYMOUSv4_computers2532540.098
2000-07-17ANONYMOUSv4_computers212550.391
2000-08-31ANONYMOUSv4_computers212560.782
2002-08-10ANONYMOUSv4_computers212571.563
2016-02-23LaurVManual testing2572581.563
2010-07-20George WoltmanManual testing2582593.127
2010-07-20George WoltmanManual testing2592606.253
2012-11-22bcp19Manual testing26026112.51
2015-09-03Sid & AndyWoody26126225.01
2016-10-19Sid & AndyWoody26226379.93
2018-11-06snme2pm1g10263264159.9
2023-08-11snme2pm1GX263264
2019-03-27Anton RepkoManual testing264265304.2
2021-10-19Ruslan BorisovManual testing265266608.5


ECM factoring results:
Total ECM effort:458,414.560 GHz-days
Estimated T-Level:51.491
DigitsB1CompleteFacMiss
20110005,892.6860.000%
25500002,391.7140.000%
30250000771.5430.000%
351000000205.4960.000%
40300000047.1380.000%
45110000009.5950.007%
50440000001.76817.063%
551100000000.29874.209%
602600000000.04795.452%
658000000000.00799.341%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002800.058
10000001000000001,7937.300
30000003000000002002.248
1100000011000000007,987361.2
430000002404906604262,5408,480
4400000044000000001,864335.8
11000000080453085763053,000391,522
260000000851710200841531057,706


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2015-04-11MadPooManual testingF39F1808E5C189692.42209e-6


PRP results:
No PRP results for M12281


CERT results:
No CERT results for M12281


P-1 factor-bounds graph:
B1 = 1000000000000, B2 = 1400160173312901000 (P-1 stage 2)
B1 = 100000000000, B2 = 121047848166084840 (P-1 stage 2)
B1 = 1000000000000 (P-1 stage 1)
B1 = 25971532008, B2 = 1947864900600 (P-1 stage 2)
B1 = 100000000000 (P-1 stage 1)
B1 = 25971532008 (P-1 stage 1)
B1 = 10000000000, B2 = 100000000000 (P-1 stage 2)
B1 = 10000000000 (P-1 stage 1)
B1 = 1000000000 (P-1 stage 1)
B1 = 43000000, B2 = 4290000000 (P-1 stage 2)
B1 = 16777216, B2 = 1677721600 (P-1 stage 2)
B1 = 8388608, B2 = 838860800 (P-1 stage 2)
B1 = 43000000 (P-1 stage 1)
B1 = 4194304, B2 = 419430400 (P-1 stage 2)
B1 = 16777216 (P-1 stage 1)
B1 = 2097152, B2 = 209715200 (P-1 stage 2)
B1 = 8388608 (P-1 stage 1)
B1 = 1048576, B2 = 104857600 (P-1 stage 2)
B1 = 1000000, B2 = 100000000 (P-1 stage 2)
B1 = 4194304 (P-1 stage 1)
B1 = 524288, B2 = 52428800 (P-1 stage 2)
B1 = 2097152 (P-1 stage 1)
B1 = 262144, B2 = 26214400 (P-1 stage 2)
B1 = 1048576 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 100000, B2 = 10000000 (P-1 stage 2)
B1 = 524288 (P-1 stage 1)
B1 = 65536, B2 = 6553600 (P-1 stage 2)
B1 = 262144 (P-1 stage 1)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 16384, B2 = 1638400 (P-1 stage 2)
B1 = 100000 (P-1 stage 1)
B1 = 65536 (P-1 stage 1)
B1 = 32768 (P-1 stage 1)
B1 = 16384 (P-1 stage 1)
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TF factor-bounds graph:
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this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=51.49 ~= 154-bit
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Last modified: 2024-02-29T14:28:04+00:00