21031232 has 28 divisors (see below), whose sum is σ = 41893236. Its totient is φ = 10475520.

The previous prime is 21031229. The next prime is 21031253. The reversal of 21031232 is 23213012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 7311616 + 13719616 = 2704^2 + 3704^2 .

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, 23432 + ... + 24312.

It is an arithmetic number, because the mean of its divisors is an integer number (1496187).

Almost surely, 2^21031232 is an apocalyptic number.

It is an amenable number.

21031232 is a deficient number, since it is larger than the sum of its proper divisors (20862004).

21031232 is an equidigital number, since it uses as much as digits as its factorization.

21031232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1266 (or 1256 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21031232 is about 4585.9821194593. The cubic root of 21031232 is about 276.0291224609.

Adding to 21031232 its reverse (23213012), we get a palindrome (44244244).

The spelling of 21031232 in words is "twenty-one million, thirty-one thousand, two hundred thirty-two".