256664420 has 48 divisors (see below), whose sum is σ = 555508800. Its totient is φ = 99555456.

The previous prime is 256664417. The next prime is 256664437. The reversal of 256664420 is 24466652.

256664420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127139 + ... + 129141.

It is an arithmetic number, because the mean of its divisors is an integer number (11573100).

Almost surely, 2^256664420 is an apocalyptic number.

256664420 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 256664420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277754400).

256664420 is an abundant number, since it is smaller than the sum of its proper divisors (298844380).

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

256664420 is a wasteful number, since it uses less digits than its factorization.

256664420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2204 (or 2202 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 35.

The square root of 256664420 is about 16020.7496703494. The cubic root of 256664420 is about 635.5092696761.

The spelling of 256664420 in words is "two hundred fifty-six million, six hundred sixty-four thousand, four hundred twenty".