216636 has 24 divisors (see below), whose sum is σ = 577920. Its totient is φ = 61872.

The previous prime is 216617. The next prime is 216641. The reversal of 216636 is 636612.

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

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 216636.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1206 + ... + 1373.

It is an arithmetic number, because the mean of its divisors is an integer number (24080).

2²¹⁶⁶³⁶ is an apocalyptic number.

It is an amenable number.

216636 is an abundant number, since it is smaller than the sum of its proper divisors (361284).

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

216636 is a wasteful number, since it uses less digits than its factorization.

216636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2593 (or 2591 counting only the distinct ones).

The product of its digits is 1296, while the sum is 24.

The square root of 216636 is about 465.4417256757. The cubic root of 216636 is about 60.0588311849.

Subtracting from 216636 its sum of digits (24), we obtain a palindrome (216612).

The spelling of 216636 in words is "two hundred sixteen thousand, six hundred thirty-six".