256322809 has 8 divisors (see below), whose sum is σ = 258469920. Its totient is φ = 254184000.

The previous prime is 256322797. The next prime is 256322839. The reversal of 256322809 is 908223652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256322809 - 2⁵ = 256322777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256322839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69994 + ... + 73564.

It is an arithmetic number, because the mean of its divisors is an integer number (32308740).

Almost surely, 2^256322809 is an apocalyptic number.

It is an amenable number.

256322809 is a deficient number, since it is larger than the sum of its proper divisors (2147111).

256322809 is a wasteful number, since it uses less digits than its factorization.

256322809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4151.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 256322809 is about 16010.0846031494. The cubic root of 256322809 is about 635.2271979286.

It can be divided in two parts, 25632 and 2809, that added together give a triangular number (28441 = T₂₃₈).

The spelling of 256322809 in words is "two hundred fifty-six million, three hundred twenty-two thousand, eight hundred nine".