21530504 has 16 divisors (see below), whose sum is σ = 40427100. Its totient is φ = 10749952.

The previous prime is 21530497. The next prime is 21530513. The reversal of 21530504 is 40503512.

It can be written as a sum of positive squares in 2 ways, for example, as 15760900 + 5769604 = 3970^2 + 2402^2 .

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, 5984 + ... + 8880.

Almost surely, 2^21530504 is an apocalyptic number.

It is an amenable number.

21530504 is a deficient number, since it is larger than the sum of its proper divisors (18896596).

21530504 is a wasteful number, since it uses less digits than its factorization.

21530504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3832 (or 3828 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 21530504 is about 4640.0974127706. The cubic root of 21530504 is about 278.1963314745.

The spelling of 21530504 in words is "twenty-one million, five hundred thirty thousand, five hundred four".