21043304 has 16 divisors (see below), whose sum is σ = 39574500. Its totient is φ = 10490112.

The previous prime is 21043301. The next prime is 21043313. The reversal of 21043304 is 40334012.

It can be written as a sum of positive squares in 2 ways, for example, as 20884900 + 158404 = 4570^2 + 398^2 .

It is not an unprimeable number, because it can be changed into a prime (21043301) 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, 977 + ... + 6560.

Almost surely, 2^21043304 is an apocalyptic number.

It is an amenable number.

21043304 is a deficient number, since it is larger than the sum of its proper divisors (18531196).

21043304 is a wasteful number, since it uses less digits than its factorization.

21043304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7892 (or 7888 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21043304 is about 4587.2981154488. The cubic root of 21043304 is about 276.0819262497.

Adding to 21043304 its reverse (40334012), we get a palindrome (61377316).

The spelling of 21043304 in words is "twenty-one million, forty-three thousand, three hundred four".