256806172 has 12 divisors (see below), whose sum is σ = 513612400. Its totient is φ = 110059776.

The previous prime is 256806163. The next prime is 256806259. The reversal of 256806172 is 271608652.

It is a happy number.

256806172 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4585797 + ... + 4585852.

Almost surely, 2^256806172 is an apocalyptic number.

It is an amenable number.

256806172 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

256806172 is a wasteful number, since it uses less digits than its factorization.

256806172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9171660 (or 9171658 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 256806172 is about 16025.1730723883. The cubic root of 256806172 is about 635.6262422986.

The spelling of 256806172 in words is "two hundred fifty-six million, eight hundred six thousand, one hundred seventy-two".