216865220 has 96 divisors (see below), whose sum is σ = 539191296. Its totient is φ = 72230400.

The previous prime is 216865163. The next prime is 216865247. The reversal of 216865220 is 22568612.

216865220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 546062 + ... + 546458.

It is an arithmetic number, because the mean of its divisors is an integer number (5616576).

Almost surely, 2^216865220 is an apocalyptic number.

216865220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216865220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269595648).

216865220 is an abundant number, since it is smaller than the sum of its proper divisors (322326076).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216865220 is a wasteful number, since it uses less digits than its factorization.

216865220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621 (or 619 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 216865220 is about 14726.3444207991. The cubic root of 216865220 is about 600.8000623226.

The spelling of 216865220 in words is "two hundred sixteen million, eight hundred sixty-five thousand, two hundred twenty".