21243532 has 12 divisors (see below), whose sum is σ = 37544976. Its totient is φ = 10516400.

The previous prime is 21243527. The next prime is 21243533. The reversal of 21243532 is 23534212.

It is not an unprimeable number, because it can be changed into a prime (21243533) 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, 25888 + ... + 26695.

It is an arithmetic number, because the mean of its divisors is an integer number (3128748).

Almost surely, 2^21243532 is an apocalyptic number.

It is an amenable number.

21243532 is a deficient number, since it is larger than the sum of its proper divisors (16301444).

21243532 is a wasteful number, since it uses less digits than its factorization.

21243532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52688 (or 52686 counting only the distinct ones).

The product of its digits is 1440, while the sum is 22.

The square root of 21243532 is about 4609.0706221537. The cubic root of 21243532 is about 276.9548076255.

Adding to 21243532 its reverse (23534212), we get a palindrome (44777744).

The spelling of 21243532 in words is "twenty-one million, two hundred forty-three thousand, five hundred thirty-two".