256393066939 has 4 divisors (see below), whose sum is σ = 261848238624. Its totient is φ = 250937895256.

The previous prime is 256393066907. The next prime is 256393066949. The reversal of 256393066939 is 939660393652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256393066939 - 2⁵ = 256393066907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256393066949) 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, 2727585772 + ... + 2727585865.

It is an arithmetic number, because the mean of its divisors is an integer number (65462059656).

Almost surely, 2^256393066939 is an apocalyptic number.

256393066939 is a deficient number, since it is larger than the sum of its proper divisors (5455171685).

256393066939 is an equidigital number, since it uses as much as digits as its factorization.

256393066939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5455171684.

The product of its (nonzero) digits is 42515280, while the sum is 61.

The spelling of 256393066939 in words is "two hundred fifty-six billion, three hundred ninety-three million, sixty-six thousand, nine hundred thirty-nine".