12661 = SUCC(12660) = 2*7! + 3*6! + 3*5! + 2*4! + 2*3! + 0*2! + 1*1! = 2332201 base factoresimal. (x! means x factorial) See notes and credits for info.
Math can be scary, but it is required for universes to exist. Don't be scared of it, understand that you don't need to know everything. If you don't, this'll happen. Now, you have to make the Math Whale canon, or the universe is gone forever. (It can be temporary though! You just gotta canonize the math!)