joke number

A Smith number is a composite number the sum of whose digits is the sum of the digits of its prime factors (excluding 1). (The primes are excluded since they trivially satisfy this condition). One example of a Smith number is the beast number 666 = 2·3·3·37, since 6 + 6 + 6 = 2 + 3 + 3 + (3 + 7) = 18. Another Smith number is 4937775 = 3·5·5·65837, since 4 + 9 + 3 + 7 + 7 + 7 + 5 = 3 + 5 + 5 + (6 + 5 + 8 + 3 + 7) = 42.

hoax number | Monica set | perfect number | repunit | Smith brothers | Suzanne set