is 2 1422721 - 1
has 428282 decimal digits
takes 0.054 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
-unknown- primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26720.885368.6567%500000150000000.07144.9168%20.956770.1978%1.5411%
PrimeNet2560.006762.5000%65001100000.00072.7708%0.007463.5391%1.0391%
GPU722600.108065.0000%6000800000.00061.3022%0.108565.4558%0.4558%
Difference+7+20.7773+3.6567%+494000+14920000+0.0709+3.6146%+20.8482+4.7420%+4.7420%

Known prime factors (1 factor, 26.0 bits, 0.00182494% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
142272165445167825.96423
23
-1233.158e-121.217e-71.217e-7

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-03-17T19:14:07alpertronManual testing5000001500000012-
skipped known factor: 65445167
--0.071--4.917%


Trial Factoring results:
No TF results for M1422721


ECM factoring results:

Old Calculation Method

Total ECM effort:26.343 GHz-days
Estimated T-Level:25.391
DigitsB1CurvesCompleteFacMiss
2011000301 / 1003.0104.855%
2550000301 / 2801.07534.064%
3025000050 / 6400.07892.479%

New Calculation Method

Total ECM effort:26.343 GHz-days
Estimated T-Level:25.391
DigitsB1CompleteFacMiss
201100014.6540.000%
25500001.67418.740%
302500000.14486.623%
3510000000.01099.005%


ECM Summary

B1B2factorcurvesGHz-days
50000500000025111.84
250000400000005014.50


Lucas-Lehmer results:
No L-L results for M1422721


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-30T20:16:07Oliver KruseGTX-3
65445167
455EC4089B4C1B__no
2017-10-26T14:28:38kkmrkkblmbrbkc4.xlarge
65445167
455EC4089B4C1B__no


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
100
101
102
103
104
105
106
100
101
102
103
104
105
106
107
108
TF factor-bounds graph:
267
220
230
240
250
260
270
280
290
2100
Last modified: 2022-03-10T10:37:56+00:00