256440729599 has 4 divisors (see below), whose sum is σ = 256466771400. Its totient is φ = 256414687800.

The previous prime is 256440729593. The next prime is 256440729679. The reversal of 256440729599 is 995927044652.

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 256440729599 - 2⁸ = 256440729343 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 (256440729593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13006124 + ... + 13025825.

It is an arithmetic number, because the mean of its divisors is an integer number (64116692850).

Almost surely, 2^256440729599 is an apocalyptic number.

256440729599 is a deficient number, since it is larger than the sum of its proper divisors (26041801).

256440729599 is an equidigital number, since it uses as much as digits as its factorization.

256440729599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26041800.

The product of its (nonzero) digits is 48988800, while the sum is 62.

The spelling of 256440729599 in words is "two hundred fifty-six billion, four hundred forty million, seven hundred twenty-nine thousand, five hundred ninety-nine".