A factorion is a positive integer with the following cute property. When written in ordinary base-10, it equals the sum of the factorizals of its digits. For example, 145 is a factorion because 1!+4!+5!=1+24+120=145. The numbers 1 and 2 are also factorions (because (1!=1 and 2!=2). There is only one other factorion; find it! We know of no nice "pencil and paper" solution to this problem. You're best off solving this with the help of a computer program.
