820580865 has 16 divisors (see below), whose sum is σ = 1413924288. Its totient is φ = 403978176.

The previous prime is 820580833. The next prime is 820580921. The reversal of 820580865 is 568085028.

It is not a de Polignac number, because 820580865 - 2⁵ = 820580833 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2103859 + ... + 2104248.

It is an arithmetic number, because the mean of its divisors is an integer number (88370268).

Almost surely, 2^820580865 is an apocalyptic number.

It is an amenable number.

820580865 is a deficient number, since it is larger than the sum of its proper divisors (593343423).

820580865 is a wasteful number, since it uses less digits than its factorization.

820580865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4208128.

The product of its (nonzero) digits is 153600, while the sum is 42.

The square root of 820580865 is about 28645.7826738946. The cubic root of 820580865 is about 936.2111198748.

The spelling of 820580865 in words is "eight hundred twenty million, five hundred eighty thousand, eight hundred sixty-five".