21022304 has 24 divisors (see below), whose sum is σ = 41497848. Its totient is φ = 10483200.

The previous prime is 21022279. The next prime is 21022357. The reversal of 21022304 is 40322012.

21022304 is nontrivially palindromic in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16904 + ... + 18104.

It is an arithmetic number, because the mean of its divisors is an integer number (1729077).

Almost surely, 2^21022304 is an apocalyptic number.

It is an amenable number.

21022304 is a deficient number, since it is larger than the sum of its proper divisors (20475544).

21022304 is a wasteful number, since it uses less digits than its factorization.

21022304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1758 (or 1750 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21022304 is about 4585.0086150410. The cubic root of 21022304 is about 275.9900577529.

Adding to 21022304 its reverse (40322012), we get a palindrome (61344316).

The spelling of 21022304 in words is "twenty-one million, twenty-two thousand, three hundred four".