256491693 has 12 divisors (see below), whose sum is σ = 372041280. Its totient is φ = 170277576.

The previous prime is 256491691. The next prime is 256491709. The reversal of 256491693 is 396194652.

256491693 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256491693 - 2¹ = 256491691 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256491691) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57471 + ... + 61772.

It is an arithmetic number, because the mean of its divisors is an integer number (31003440).

Almost surely, 2^256491693 is an apocalyptic number.

It is an amenable number.

256491693 is a deficient number, since it is larger than the sum of its proper divisors (115549587).

256491693 is a wasteful number, since it uses less digits than its factorization.

256491693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119488 (or 119485 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 256491693 is about 16015.3580353360. The cubic root of 256491693 is about 635.3666785025.

The spelling of 256491693 in words is "two hundred fifty-six million, four hundred ninety-one thousand, six hundred ninety-three".