21132304 has 20 divisors (see below), whose sum is σ = 41344576. Its totient is φ = 10462752.

The previous prime is 21132301. The next prime is 21132311. The reversal of 21132304 is 40323112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (21132301) 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, 4764 + ... + 8059.

Almost surely, 2^21132304 is an apocalyptic number.

It is an amenable number.

21132304 is a deficient number, since it is larger than the sum of its proper divisors (20212272).

21132304 is a wasteful number, since it uses less digits than its factorization.

21132304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12934 (or 12928 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21132304 is about 4596.9885794942. The cubic root of 21132304 is about 276.4705967140.

Adding to 21132304 its reverse (40323112), we get a palindrome (61455416).

The spelling of 21132304 in words is "twenty-one million, one hundred thirty-two thousand, three hundred four".