21823216 has 20 divisors (see below), whose sum is σ = 42365592. Its totient is φ = 10890176.

The previous prime is 21823211. The next prime is 21823247. The reversal of 21823216 is 61232812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21823211) 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, 9930 + ... + 11926.

Almost surely, 2^21823216 is an apocalyptic number.

It is an amenable number.

21823216 is a deficient number, since it is larger than the sum of its proper divisors (20542376).

21823216 is a wasteful number, since it uses less digits than its factorization.

21823216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2688 (or 2682 counting only the distinct ones).

The product of its digits is 1152, while the sum is 25.

The square root of 21823216 is about 4671.5325108577. The cubic root of 21823216 is about 279.4513747185.

The spelling of 21823216 in words is "twenty-one million, eight hundred twenty-three thousand, two hundred sixteen".