21043232 has 48 divisors (see below), whose sum is σ = 48646080. Its totient is φ = 8771328.

The previous prime is 21043223. The next prime is 21043237. The reversal of 21043232 is 23234012.

It is a super-2 number, since 2×21043232² = 885635226011648, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21043232.

It is not an unprimeable number, because it can be changed into a prime (21043237) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7019 + ... + 9557.

It is an arithmetic number, because the mean of its divisors is an integer number (1013460).

Almost surely, 2^21043232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21043232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24323040).

21043232 is an abundant number, since it is smaller than the sum of its proper divisors (27602848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21043232 is a wasteful number, since it uses less digits than its factorization.

21043232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2593 (or 2585 counting only the distinct ones).

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

The square root of 21043232 is about 4587.2902676853. The cubic root of 21043232 is about 276.0816113764.

Adding to 21043232 its reverse (23234012), we get a palindrome (44277244).

The spelling of 21043232 in words is "twenty-one million, forty-three thousand, two hundred thirty-two".