256838457693 has 4 divisors (see below), whose sum is σ = 342451276928. Its totient is φ = 171225638460.

The previous prime is 256838457691. The next prime is 256838457703. The reversal of 256838457693 is 396754838652.

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 not a de Polignac number, because 256838457693 - 2¹ = 256838457691 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 (256838457691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42806409613 + ... + 42806409618.

It is an arithmetic number, because the mean of its divisors is an integer number (85612819232).

Almost surely, 2^256838457693 is an apocalyptic number.

It is an amenable number.

256838457693 is a deficient number, since it is larger than the sum of its proper divisors (85612819235).

256838457693 is an equidigital number, since it uses as much as digits as its factorization.

256838457693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85612819234.

The product of its digits is 261273600, while the sum is 66.

The spelling of 256838457693 in words is "two hundred fifty-six billion, eight hundred thirty-eight million, four hundred fifty-seven thousand, six hundred ninety-three".