820518865 has 8 divisors (see below), whose sum is σ = 989290368. Its totient is φ = 653303280.

The previous prime is 820518863. The next prime is 820518871. The reversal of 820518865 is 568815028.

820518865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 820518865 - 2¹ = 820518863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820518863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 387817 + ... + 389926.

It is an arithmetic number, because the mean of its divisors is an integer number (123661296).

Almost surely, 2^820518865 is an apocalyptic number.

It is an amenable number.

820518865 is a deficient number, since it is larger than the sum of its proper divisors (168771503).

820518865 is a wasteful number, since it uses less digits than its factorization.

820518865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777959.

The product of its (nonzero) digits is 153600, while the sum is 43.

The square root of 820518865 is about 28644.7004697204. The cubic root of 820518865 is about 936.1875404187.

The spelling of 820518865 in words is "eight hundred twenty million, five hundred eighteen thousand, eight hundred sixty-five".