216505212 has 96 divisors (see below), whose sum is σ = 641862144. Its totient is φ = 55161600.

The previous prime is 216505193. The next prime is 216505229. The reversal of 216505212 is 212505612.

It is a happy number.

216505212 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

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, 46762 + ... + 51182.

It is an arithmetic number, because the mean of its divisors is an integer number (6686064).

Almost surely, 2^216505212 is an apocalyptic number.

216505212 is a gapful number since it is divisible by the number (22) 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 216505212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (320931072).

216505212 is an abundant number, since it is smaller than the sum of its proper divisors (425356932).

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

216505212 is a wasteful number, since it uses less digits than its factorization.

216505212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4499 (or 4497 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 216505212 is about 14714.1160794660. The cubic root of 216505212 is about 600.4674246513.

It can be divided in two parts, 21650 and 5212, that added together give a palindrome (26862).

The spelling of 216505212 in words is "two hundred sixteen million, five hundred five thousand, two hundred twelve".