256664193 has 4 divisors (see below), whose sum is σ = 342218928. Its totient is φ = 171109460.

The previous prime is 256664183. The next prime is 256664197. The reversal of 256664193 is 391466652.

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 not a de Polignac number, because 256664193 - 2⁸ = 256663937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256664197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42777363 + ... + 42777368.

It is an arithmetic number, because the mean of its divisors is an integer number (85554732).

Almost surely, 2^256664193 is an apocalyptic number.

It is an amenable number.

256664193 is a deficient number, since it is larger than the sum of its proper divisors (85554735).

256664193 is an equidigital number, since it uses as much as digits as its factorization.

256664193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85554734.

The product of its digits is 233280, while the sum is 42.

The square root of 256664193 is about 16020.7425857855. The cubic root of 256664193 is about 635.5090823230.

The spelling of 256664193 in words is "two hundred fifty-six million, six hundred sixty-four thousand, one hundred ninety-three".