216660920 has 128 divisors (see below), whose sum is σ = 615859200. Its totient is φ = 66840576.

The previous prime is 216660911. The next prime is 216660923. The reversal of 216660920 is 29066612.

216660920 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216660923) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108491 + ... + 110469.

It is an arithmetic number, because the mean of its divisors is an integer number (4811400).

Almost surely, 2^216660920 is an apocalyptic number.

216660920 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 216660920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307929600).

216660920 is an abundant number, since it is smaller than the sum of its proper divisors (399198280).

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

216660920 is a wasteful number, since it uses less digits than its factorization.

216660920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2037 (or 2033 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 216660920 is about 14719.4062380247. The cubic root of 216660920 is about 600.6113398574.

The spelling of 216660920 in words is "two hundred sixteen million, six hundred sixty thousand, nine hundred twenty".