216111720 has 128 divisors (see below), whose sum is σ = 714718080. Its totient is φ = 51840000.

The previous prime is 216111691. The next prime is 216111733. The reversal of 216111720 is 27111612.

It is a happy 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 31 ways as a sum of consecutive naturals, for example, 132510 + ... + 134130.

It is an arithmetic number, because the mean of its divisors is an integer number (5583735).

Almost surely, 2^216111720 is an apocalyptic number.

216111720 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 216111720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (357359040).

216111720 is an abundant number, since it is smaller than the sum of its proper divisors (498606360).

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

216111720 is a wasteful number, since it uses less digits than its factorization.

216111720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1747 (or 1743 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 21.

The square root of 216111720 is about 14700.7387569469. The cubic root of 216111720 is about 600.1034266150.

The spelling of 216111720 in words is "two hundred sixteen million, one hundred eleven thousand, seven hundred twenty".