216216 has 128 divisors (see below), whose sum is σ = 806400. Its totient is φ = 51840.

The previous prime is 216211. The next prime is 216217. The reversal of 216216 is 612612.

Added to its reverse (612612) it gives a triangular number (828828 = T₁₂₈₇).

216216 = 3³ + 4³ + ... + 30³.

It is a happy number.

216216 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (144) is a multiple of the sum of its prime divisors (36).

It is a nialpdrome in base 13.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216216.

It is not an unprimeable number, because it can be changed into a prime (216211) by changing a digit.

216216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16626 + ... + 16638.

It is an arithmetic number, because the mean of its divisors is an integer number (6300).

2²¹⁶²¹⁶ is an apocalyptic number.

216216 is a gapful number since it is divisible by the number (26) 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 216216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (403200).

216216 is an abundant number, since it is smaller than the sum of its proper divisors (590184).

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

216216 is a wasteful number, since it uses less digits than its factorization.

216216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46 (or 36 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 216216 is about 464.9903224799. The cubic root of 216216 is about 60.0199933370.

Adding to 216216 its reverse (612612), we get a palindrome (828828).

The spelling of 216216 in words is "two hundred sixteen thousand, two hundred sixteen".