21432732 has 24 divisors (see below), whose sum is σ = 50528016. Its totient is φ = 7070208.

The previous prime is 21432701. The next prime is 21432737. The reversal of 21432732 is 23723412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8043 + ... + 10370.

It is an arithmetic number, because the mean of its divisors is an integer number (2105334).

Almost surely, 2^21432732 is an apocalyptic number.

It is an amenable number.

21432732 is an abundant number, since it is smaller than the sum of its proper divisors (29095284).

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

21432732 is a wasteful number, since it uses less digits than its factorization.

21432732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18517 (or 18515 counting only the distinct ones).

The product of its digits is 2016, while the sum is 24.

The square root of 21432732 is about 4629.5498701278. The cubic root of 21432732 is about 277.7745873885.

The spelling of 21432732 in words is "twenty-one million, four hundred thirty-two thousand, seven hundred thirty-two".