216503505 has 12 divisors (see below), whose sum is σ = 375272820. Its totient is φ = 115468512.

The previous prime is 216503467. The next prime is 216503533. The reversal of 216503505 is 505305612.

216503505 is a `hidden beast` number, since 2 + 1 + 650 + 3 + 5 + 0 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 40755456 + 175748049 = 6384^2 + 13257^2 .

It is not a de Polignac number, because 216503505 - 2⁸ = 216503249 is a prime.

It is a Curzon number.

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, 2405550 + ... + 2405639.

It is an arithmetic number, because the mean of its divisors is an integer number (31272735).

Almost surely, 2^216503505 is an apocalyptic number.

It is an amenable number.

216503505 is a deficient number, since it is larger than the sum of its proper divisors (158769315).

216503505 is a wasteful number, since it uses less digits than its factorization.

216503505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4811200 (or 4811197 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 216503505 is about 14714.0580738286. The cubic root of 216503505 is about 600.4658465514.

The spelling of 216503505 in words is "two hundred sixteen million, five hundred three thousand, five hundred five".