256817225136 has 80 divisors (see below), whose sum is σ = 695988668160. Its totient is φ = 81489649920.

The previous prime is 256817225099. The next prime is 256817225167. The reversal of 256817225136 is 631522718652.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1200430 + ... + 1398093.

It is an arithmetic number, because the mean of its divisors is an integer number (8699858352).

Almost surely, 2^256817225136 is an apocalyptic number.

It is an amenable number.

256817225136 is an abundant number, since it is smaller than the sum of its proper divisors (439171443024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256817225136 is a wasteful number, since it uses less digits than its factorization.

256817225136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2598634 (or 2598628 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 48.

The spelling of 256817225136 in words is "two hundred fifty-six billion, eight hundred seventeen million, two hundred twenty-five thousand, one hundred thirty-six".