256518864 has 120 divisors (see below), whose sum is σ = 825756672. Its totient is φ = 72817920.

The previous prime is 256518851. The next prime is 256518869. The reversal of 256518864 is 468815652.

256518864 is a `hidden beast` number, since 2 + 56 + 518 + 86 + 4 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256518869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 173649 + ... + 175119.

Almost surely, 2^256518864 is an apocalyptic number.

256518864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256518864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (412878336).

256518864 is an abundant number, since it is smaller than the sum of its proper divisors (569237808).

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

256518864 is a wasteful number, since it uses less digits than its factorization.

256518864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1665 (or 1656 counting only the distinct ones).

The product of its digits is 460800, while the sum is 45.

The square root of 256518864 is about 16016.2062923777. The cubic root of 256518864 is about 635.3891131972.

The spelling of 256518864 in words is "two hundred fifty-six million, five hundred eighteen thousand, eight hundred sixty-four".