21542432 has 12 divisors (see below), whose sum is σ = 42411726. Its totient is φ = 10771200.

The previous prime is 21542413. The next prime is 21542453. The reversal of 21542432 is 23424512.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20830096 + 712336 = 4564^2 + 844^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21542398 and 21542407.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 336569 + ... + 336632.

Almost surely, 2^21542432 is an apocalyptic number.

It is an amenable number.

21542432 is a deficient number, since it is larger than the sum of its proper divisors (20869294).

21542432 is an equidigital number, since it uses as much as digits as its factorization.

21542432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673211 (or 673203 counting only the distinct ones).

The product of its digits is 1920, while the sum is 23.

The square root of 21542432 is about 4641.3825526453. The cubic root of 21542432 is about 278.2476960136.

Adding to 21542432 its reverse (23424512), we get a palindrome (44966944).

The spelling of 21542432 in words is "twenty-one million, five hundred forty-two thousand, four hundred thirty-two".