216573865 has 16 divisors (see below), whose sum is σ = 271958400. Its totient is φ = 165255552.

The previous prime is 216573857. The next prime is 216573881. The reversal of 216573865 is 568375612.

It is not a de Polignac number, because 216573865 - 2³ = 216573857 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, 41101 + ... + 46069.

It is an arithmetic number, because the mean of its divisors is an integer number (16997400).

Almost surely, 2^216573865 is an apocalyptic number.

It is an amenable number.

216573865 is a deficient number, since it is larger than the sum of its proper divisors (55384535).

216573865 is a wasteful number, since it uses less digits than its factorization.

216573865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5376.

The product of its digits is 302400, while the sum is 43.

The square root of 216573865 is about 14716.4487903842. The cubic root of 216573865 is about 600.5308866086.

The spelling of 216573865 in words is "two hundred sixteen million, five hundred seventy-three thousand, eight hundred sixty-five".