is 2 12526721 - 1
has 3770919 decimal digits
takes 4.823 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LF1ED6BF72B7F18C7double-checked
PRP8AE30B1BBDAF4893PRP-tested

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual2684.758264.7059%15000021750000.14533.3518%4.903565.8889%
Target2684.758264.7059%9000022000000.11443.0913%4.872665.7969%
Difference---+60000-25000+0.0309+0.2605%+0.0309+0.0919%

Known prime factors (1 factor, 66.6 bits, 0.00053154% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
125267211106386127925482677512166.5844416104293875
32 × 53 × 2213 × 1773803
2015-03-22221317738031.50820.05510.1008

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-03-17ANONYMOUSv4_computers1500002175000---0.145--3.352%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2000-03-22ANONYMOUSv4_computers21255--0.000--
2000-03-22ANONYMOUSv4_computers21256--0.001--
2000-04-05MadPoov4_computers21264--0.284--
2013-06-20lycornManual testing264265--0.298--
2014-03-28NesowaManual testing265266--0.597--
2015-03-22ThaManual testing26626766.584210.32912.150.829
2022-04-10LordJuliusManual testing267268--2.386--


ECM factoring results:
No ECM results for M12526721


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2001-04-29ANONYMOUSv4_computersF1ED6BF72B7F18C74.823
2004-08-06monstv4_computersF1ED6BF72B7F18C74.823


PRP results:
dateuseridcompidcofactorsres64PRP
2022-04-16kutensterra
110638612792548267751
8AE30B1BBDAF4893no


P-1 factor-bounds graph:
B1 = 150000, B2 = 2175000 (P-1 stage 2)
B1 = 150000 (P-1 stage 1)
102
103
104
105
106
102
103
104
105
106
107
TF factor-bounds graph:
268
267
266
265
264
256
255
this exponent TF target: 68
TF double-checked to: 67.7
250
260
270
Last modified: 2023-03-25T13:08:14+00:00