-- Find the sum of all numbers which are equal to the sum of the factorial of their digits.
--
-- Note: as 1! = 1 and 2! = 2 are not sums they are not included.

import Euler

factorial n = product [1..n]
factSum n = sum $ map factorial $ toDigits n

main = print $ sum $ filter (\n -> n == factSum n) [10..2540160]