21753232 has 20 divisors (see below), whose sum is σ = 42219520. Its totient is φ = 10857888.

The previous prime is 21753209. The next prime is 21753257. The reversal of 21753232 is 23235712.

It is a junction number, because it is equal to n+sod(n) for n = 21753197 and 21753206.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16369 + ... + 17647.

It is an arithmetic number, because the mean of its divisors is an integer number (2110976).

Almost surely, 2^21753232 is an apocalyptic number.

It is an amenable number.

21753232 is a deficient number, since it is larger than the sum of its proper divisors (20466288).

21753232 is a wasteful number, since it uses less digits than its factorization.

21753232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2350 (or 2344 counting only the distinct ones).

The product of its digits is 2520, while the sum is 25.

The square root of 21753232 is about 4664.0360204441. The cubic root of 21753232 is about 279.1523343450.

Adding to 21753232 its reverse (23235712), we get a palindrome (44988944).

The spelling of 21753232 in words is "twenty-one million, seven hundred fifty-three thousand, two hundred thirty-two".