216500865 has 48 divisors (see below), whose sum is σ = 426684672. Its totient is φ = 93144576.

The previous prime is 216500857. The next prime is 216500891. The reversal of 216500865 is 568005612.

It is not a de Polignac number, because 216500865 - 2³ = 216500857 is a prime.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 3832 + ... + 21158.

It is an arithmetic number, because the mean of its divisors is an integer number (8889264).

Almost surely, 2^216500865 is an apocalyptic number.

It is an amenable number.

216500865 is a deficient number, since it is larger than the sum of its proper divisors (210183807).

216500865 is a wasteful number, since it uses less digits than its factorization.

216500865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17366 (or 17359 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 216500865 is about 14713.9683634294. The cubic root of 216500865 is about 600.4634058884.

The spelling of 216500865 in words is "two hundred sixteen million, five hundred thousand, eight hundred sixty-five".