is 2 12255877 - 1
has 3689387 decimal digits
takes 4.719 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L1DC5ADBA997518C2double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual27278.030666.6667 %1000000225026802068.96978.9168 %147.000469.6389 %
Target2684.863464.7059 %90000110000000.38213.0813 %5.245465.7934 %
Difference+4+73.1672+1.9608 %+910000+2239268020+68.5877+5.8355%+141.7549+3.8455 %

Known prime factors (1 factor, 90.0 bits, 0.00073460% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1225587712659249485544413001497557672890.03251645628809527106879
35 × 73 × 23 × 283 × 359 × 265170041
2021-12-2135926517004137,105,2688.065315.063

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2004-04-29dave_0273v4_computers7000013125006--0.0772.606%
2015-05-13Sid & AndySpeck12500020937506--0.1303.222%
2021-12-21LuminescenceW-22951000000225026802022890.03285.7912.149%


Trial Factoring results:
57585960616263646566676869707172
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2000-03-08ANONYMOUSv4_computers212640.160
2013-08-12lycornManual testing2642650.305
2013-09-29NesowaManual testing2652660.610
2015-03-05ThaManual testing2662671.219
2015-07-25ThaManual testing2672682.439
2017-11-03ramgeisManual testing2682694.878
2021-07-29ZacHFXManual testing26927129.27
2021-10-22ANONYMOUSManual testing27127239.02


ECM factoring results:
Total ECM effort:1.171 GHz-days
Estimated T-Level:0.385
DigitsB1CompleteFacMiss
20110000.07792.596%
25500000.00799.291%


ECM Summary

B1B2factorcurvesGHz-days
50000500000021.171


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2001-07-17ANONYMOUSv4_computers1DC5ADBA997518C24.719
2004-06-21ANONYMOUSv4_computers1DC5ADBA997518C24.719


PRP results:
dateuseridcompidcofactorsres64
2022-02-20GANLMS-11
1265924948554441300149755767
541B50BD5031F188


CERT results:
dateuseridcompid
2022-02-20march


P-1 factor-bounds graph:
B1 = 1000000, B2 = 2250268020 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 125000, B2 = 2093750 (P-1 stage 2)
B1 = 70000, B2 = 1312500 (P-1 stage 2)
B1 = 125000 (P-1 stage 1)
B1 = 70000 (P-1 stage 1)
101
102
103
104
105
106
101
102
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
272
271
269
268
267
266
265
264
this exponent TF target: 68
TF double-checked to: 67
ECM T-Level=0.38 ~= -15-bit
250
260
270
280
290
2100
JSON version of this page
Last modified: 2024-03-13T02:15:48+00:00