256385693 has 4 divisors (see below), whose sum is σ = 256562880. Its totient is φ = 256208508.

The previous prime is 256385671. The next prime is 256385719. The reversal of 256385693 is 396583652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256385693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256385093) 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, 86405 + ... + 89322.

It is an arithmetic number, because the mean of its divisors is an integer number (64140720).

Almost surely, 2^256385693 is an apocalyptic number.

It is an amenable number.

256385693 is a deficient number, since it is larger than the sum of its proper divisors (177187).

256385693 is a wasteful number, since it uses less digits than its factorization.

256385693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177186.

The product of its digits is 1166400, while the sum is 47.

The square root of 256385693 is about 16012.0483698995. The cubic root of 256385693 is about 635.2791407126.

The spelling of 256385693 in words is "two hundred fifty-six million, three hundred eighty-five thousand, six hundred ninety-three".