256238172 has 72 divisors (see below), whose sum is σ = 679538496. Its totient is φ = 81316224.

The previous prime is 256238167. The next prime is 256238179. The reversal of 256238172 is 271832652.

256238172 is a `hidden beast` number, since 25 + 623 + 8 + 1 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256238179) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60558 + ... + 64650.

Almost surely, 2^256238172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256238172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (339769248).

256238172 is an abundant number, since it is smaller than the sum of its proper divisors (423300324).

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

256238172 is a wasteful number, since it uses less digits than its factorization.

256238172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4187 (or 4182 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 256238172 is about 16007.4411446677. The cubic root of 256238172 is about 635.1572735454.

The spelling of 256238172 in words is "two hundred fifty-six million, two hundred thirty-eight thousand, one hundred seventy-two".