21040232 has 16 divisors (see below), whose sum is σ = 39557700. Its totient is φ = 10491520.

The previous prime is 21040231. The next prime is 21040247. The reversal of 21040232 is 23204012.

It can be written as a sum of positive squares in 2 ways, for example, as 21031396 + 8836 = 4586^2 + 94^2 .

It is a super-2 number, since 2×21040232² = 885382725227648, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21040231) 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, 269 + ... + 6492.

Almost surely, 2^21040232 is an apocalyptic number.

It is an amenable number.

21040232 is a deficient number, since it is larger than the sum of its proper divisors (18517468).

21040232 is a wasteful number, since it uses less digits than its factorization.

21040232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7156 (or 7152 counting only the distinct ones).

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

The square root of 21040232 is about 4586.9632656039. The cubic root of 21040232 is about 276.0684910187.

Adding to 21040232 its reverse (23204012), we get a palindrome (44244244).

The spelling of 21040232 in words is "twenty-one million, forty thousand, two hundred thirty-two".