sentences:  formula_16 and formula_17 are fixed points for all formula_1, and thus are trivial factorions for all formula_1, and all other factorions are nontrivial factorions.For example, the number 145 in base formula_20 is a factorion because formula_21.For formula_22, the sum of the factorial of the digits is simply the number of digits formula_23 in the base 2 representation.