816664635 has 12 divisors (see below), whose sum is σ = 1415552112. Its totient is φ = 435554448.

The previous prime is 816664627. The next prime is 816664661. The reversal of 816664635 is 536466618.

It is not a de Polignac number, because 816664635 - 2³ = 816664627 is a prime.

It is a super-2 number, since 2×816664635² = 1333882252119366450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 18148103 = 816664635 / (8 + 1 + 6 + 6 + 6 + 4 + 6 + 3 + 5).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9074007 + ... + 9074096.

It is an arithmetic number, because the mean of its divisors is an integer number (117962676).

Almost surely, 2^816664635 is an apocalyptic number.

816664635 is a deficient number, since it is larger than the sum of its proper divisors (598887477).

816664635 is a wasteful number, since it uses less digits than its factorization.

816664635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18148114 (or 18148111 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 816664635 is about 28577.3447856864. The cubic root of 816664635 is about 934.7193854151.

The spelling of 816664635 in words is "eight hundred sixteen million, six hundred sixty-four thousand, six hundred thirty-five".