816585905 has 16 divisors (see below), whose sum is σ = 1082657664. Its totient is φ = 588107520.

The previous prime is 816585877. The next prime is 816585919. The reversal of 816585905 is 509585618.

It is not a de Polignac number, because 816585905 - 2⁶ = 816585841 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 816585905.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 206891 + ... + 210800.

It is an arithmetic number, because the mean of its divisors is an integer number (67666104).

Almost surely, 2^816585905 is an apocalyptic number.

816585905 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

816585905 is a deficient number, since it is larger than the sum of its proper divisors (266071759).

816585905 is a wasteful number, since it uses less digits than its factorization.

816585905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417736.

The product of its (nonzero) digits is 432000, while the sum is 47.

The square root of 816585905 is about 28575.9672627192. The cubic root of 816585905 is about 934.6893474538.

The spelling of 816585905 in words is "eight hundred sixteen million, five hundred eighty-five thousand, nine hundred five".