216633 has 4 divisors (see below), whose sum is σ = 288848. Its totient is φ = 144420.

The previous prime is 216617. The next prime is 216641. The reversal of 216633 is 336612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 216633 - 2⁴ = 216617 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36103 + ... + 36108.

It is an arithmetic number, because the mean of its divisors is an integer number (72212).

2²¹⁶⁶³³ is an apocalyptic number.

It is an amenable number.

216633 is a deficient number, since it is larger than the sum of its proper divisors (72215).

216633 is an equidigital number, since it uses as much as digits as its factorization.

216633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72214.

The product of its digits is 648, while the sum is 21.

The square root of 216633 is about 465.4385029196. The cubic root of 216633 is about 60.0585539498.

Subtracting from 216633 its sum of digits (21), we obtain a palindrome (216612).

The spelling of 216633 in words is "two hundred sixteen thousand, six hundred thirty-three".