256618 has 8 divisors (see below), whose sum is σ = 397440. Its totient is φ = 124140.

The previous prime is 256609. The next prime is 256639. The reversal of 256618 is 816652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2008 + ... + 2131.

It is an arithmetic number, because the mean of its divisors is an integer number (49680).

2²⁵⁶⁶¹⁸ is an apocalyptic number.

256618 is a deficient number, since it is larger than the sum of its proper divisors (140822).

256618 is a wasteful number, since it uses less digits than its factorization.

256618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4172.

The product of its digits is 2880, while the sum is 28.

The square root of 256618 is about 506.5747723683. The cubic root of 256618 is about 63.5470954901.

The spelling of 256618 in words is "two hundred fifty-six thousand, six hundred eighteen".