256385805 has 32 divisors (see below), whose sum is σ = 443439360. Its totient is φ = 125744640.

The previous prime is 256385749. The next prime is 256385819. The reversal of 256385805 is 508583652.

It is not a de Polignac number, because 256385805 - 2¹³ = 256377613 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52456 + ... + 57134.

It is an arithmetic number, because the mean of its divisors is an integer number (13857480).

Almost surely, 2^256385805 is an apocalyptic number.

It is an amenable number.

256385805 is a deficient number, since it is larger than the sum of its proper divisors (187053555).

256385805 is a wasteful number, since it uses less digits than its factorization.

256385805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4981.

The product of its (nonzero) digits is 288000, while the sum is 42.

The square root of 256385805 is about 16012.0518672655. The cubic root of 256385805 is about 635.2792332181.

The spelling of 256385805 in words is "two hundred fifty-six million, three hundred eighty-five thousand, eight hundred five".