256788017 has 4 divisors (see below), whose sum is σ = 257608740. Its totient is φ = 255967296.

The previous prime is 256788013. The next prime is 256788041. The reversal of 256788017 is 710887652.

256788017 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 70492816 + 186295201 = 8396^2 + 13649^2 .

It is a cyclic number.

It is not a de Polignac number, because 256788017 - 2² = 256788013 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256788013) 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, 409892 + ... + 410517.

It is an arithmetic number, because the mean of its divisors is an integer number (64402185).

Almost surely, 2^256788017 is an apocalyptic number.

It is an amenable number.

256788017 is a deficient number, since it is larger than the sum of its proper divisors (820723).

256788017 is an equidigital number, since it uses as much as digits as its factorization.

256788017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820722.

The product of its (nonzero) digits is 188160, while the sum is 44.

The square root of 256788017 is about 16024.6066098360. The cubic root of 256788017 is about 635.6112633409.

The spelling of 256788017 in words is "two hundred fifty-six million, seven hundred eighty-eight thousand, seventeen".