216216720 has 60 divisors (see below), whose sum is σ = 726130236. Its totient is φ = 57657600.

The previous prime is 216216701. The next prime is 216216809. The reversal of 216216720 is 27612612.

216216720 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 65221776 + 150994944 = 8076^2 + 12288^2 .

It is a tau number, because it is divible by the number of its divisors (60).

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, 149431 + ... + 150870.

Almost surely, 2^216216720 is an apocalyptic number.

216216720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216216720 is an abundant number, since it is smaller than the sum of its proper divisors (509913516).

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

216216720 is a wasteful number, since it uses less digits than its factorization.

216216720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300320 (or 300311 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 216216720 is about 14704.3095723669. The cubic root of 216216720 is about 600.2005995922.

The spelling of 216216720 in words is "two hundred sixteen million, two hundred sixteen thousand, seven hundred twenty".