816865259 has 4 divisors (see below), whose sum is σ = 933560304. Its totient is φ = 700170216.

The previous prime is 816865253. The next prime is 816865261. The reversal of 816865259 is 952568618.

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 816865259 - 2²⁸ = 548429803 is a prime.

It is a super-2 number, since 2×816865259² = 1334537702722274162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816865253) 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 3 ways as a sum of consecutive naturals, for example, 58347512 + ... + 58347525.

It is an arithmetic number, because the mean of its divisors is an integer number (233390076).

Almost surely, 2^816865259 is an apocalyptic number.

816865259 is a deficient number, since it is larger than the sum of its proper divisors (116695045).

816865259 is a wasteful number, since it uses less digits than its factorization.

816865259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116695044.

The product of its digits is 1036800, while the sum is 50.

The square root of 816865259 is about 28580.8547632852. The cubic root of 816865259 is about 934.7959210292.

The spelling of 816865259 in words is "eight hundred sixteen million, eight hundred sixty-five thousand, two hundred fifty-nine".