256404580 has 12 divisors (see below), whose sum is σ = 538449660. Its totient is φ = 102561824.

The previous prime is 256404539. The next prime is 256404581. The reversal of 256404580 is 85404652.

It can be written as a sum of positive squares in 2 ways, for example, as 123832384 + 132572196 = 11128^2 + 11514^2 .

It is not an unprimeable number, because it can be changed into a prime (256404581) 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 3 ways as a sum of consecutive naturals, for example, 6410095 + ... + 6410134.

It is an arithmetic number, because the mean of its divisors is an integer number (44870805).

Almost surely, 2^256404580 is an apocalyptic number.

256404580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256404580 is an abundant number, since it is smaller than the sum of its proper divisors (282045080).

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

256404580 is a wasteful number, since it uses less digits than its factorization.

256404580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12820238 (or 12820236 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 34.

The square root of 256404580 is about 16012.6381336743. The cubic root of 256404580 is about 635.2947398962.

The spelling of 256404580 in words is "two hundred fifty-six million, four hundred four thousand, five hundred eighty".