256568820 has 48 divisors (see below), whose sum is σ = 719734848. Its totient is φ = 68290560.

The previous prime is 256568801. The next prime is 256568821. The reversal of 256568820 is 28865652.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256568821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30915 + ... + 38325.

It is an arithmetic number, because the mean of its divisors is an integer number (14994476).

Almost surely, 2^256568820 is an apocalyptic number.

256568820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256568820 is an abundant number, since it is smaller than the sum of its proper divisors (463166028).

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

256568820 is a wasteful number, since it uses less digits than its factorization.

256568820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8000 (or 7998 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 42.

The square root of 256568820 is about 16017.7657618034. The cubic root of 256568820 is about 635.4303569973.

The spelling of 256568820 in words is "two hundred fifty-six million, five hundred sixty-eight thousand, eight hundred twenty".