216320 has 54 divisors (see below), whose sum is σ = 561078. Its totient is φ = 79872.

The previous prime is 216319. The next prime is 216329. The reversal of 216320 is 23612.

It can be written as a sum of positive squares in 3 ways, for example, as 1024 + 215296 = 32^2 + 464^2 .

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 216295 and 216304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216329) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16634 + ... + 16646.

2²¹⁶³²⁰ is an apocalyptic number.

216320 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 216320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280539).

216320 is an abundant number, since it is smaller than the sum of its proper divisors (344758).

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

216320 is an equidigital number, since it uses as much as digits as its factorization.

216320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 216320 is about 465.1021393200. The cubic root of 216320 is about 60.0296150097.

Adding to 216320 its reverse (23612), we get a palindrome (239932).

It can be divided in two parts, 2 and 16320, that multiplied together give a triangular number (32640 = T₂₅₅).

The spelling of 216320 in words is "two hundred sixteen thousand, three hundred twenty".