256656620 has 48 divisors (see below), whose sum is σ = 593526528. Its totient is φ = 92448960.

The previous prime is 256656619. The next prime is 256656623. The reversal of 256656620 is 26656652.

256656620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (256656623) 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, 18089 + ... + 28991.

It is an arithmetic number, because the mean of its divisors is an integer number (12365136).

Almost surely, 2^256656620 is an apocalyptic number.

256656620 is a gapful number since it is divisible by the number (20) 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 256656620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (296763264).

256656620 is an abundant number, since it is smaller than the sum of its proper divisors (336869908).

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

256656620 is a wasteful number, since it uses less digits than its factorization.

256656620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11030 (or 11028 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 256656620 is about 16020.5062341987. The cubic root of 256656620 is about 635.5028319282.

The spelling of 256656620 in words is "two hundred fifty-six million, six hundred fifty-six thousand, six hundred twenty".