66216 has 32 divisors (see below), whose sum is σ = 172800. Its totient is φ = 21120.

The previous prime is 66191. The next prime is 66221. The reversal of 66216 is 61266.

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

It is a junction number, because it is equal to n+sod(n) for n = 66192 and 66201.

It is an unprimeable number.

66216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 700 + ... + 788.

It is an arithmetic number, because the mean of its divisors is an integer number (5400).

2⁶⁶²¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86400).

66216 is an abundant number, since it is smaller than the sum of its proper divisors (106584).

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

66216 is a wasteful number, since it uses less digits than its factorization.

66216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 125 counting only the distinct ones).

The product of its digits is 432, while the sum is 21.

The square root of 66216 is about 257.3246976098. The cubic root of 66216 is about 40.4564384541.

Subtracting from 66216 its reverse (61266), we obtain a triangular number (4950 = T₉₉).

It can be divided in two parts, 66 and 216, that added together give a palindrome (282).

The spelling of 66216 in words is "sixty-six thousand, two hundred sixteen".