216720240 has 160 divisors (see below), whose sum is σ = 740952576. Its totient is φ = 51962880.

The previous prime is 216720227. The next prime is 216720247. The reversal of 216720240 is 42027612.

216720240 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 216720240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216720247) 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, 271522 + ... + 272318.

Almost surely, 2^216720240 is an apocalyptic number.

216720240 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 216720240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (370476288).

216720240 is an abundant number, since it is smaller than the sum of its proper divisors (524232336).

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

216720240 is a wasteful number, since it uses less digits than its factorization.

216720240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 927 (or 921 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 216720240 is about 14721.4211270516. The cubic root of 216720240 is about 600.6661490243. Note that the first 3 decimals are identical.

Adding to 216720240 its reverse (42027612), we get a palindrome (258747852).

The spelling of 216720240 in words is "two hundred sixteen million, seven hundred twenty thousand, two hundred forty".