21523732 has 12 divisors (see below), whose sum is σ = 39649120. Its totient is φ = 10195416.

The previous prime is 21523727. The next prime is 21523739. The reversal of 21523732 is 23732512.

It is a junction number, because it is equal to n+sod(n) for n = 21523697 and 21523706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21523739) 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, 141528 + ... + 141679.

Almost surely, 2^21523732 is an apocalyptic number.

It is an amenable number.

21523732 is a deficient number, since it is larger than the sum of its proper divisors (18125388).

21523732 is a wasteful number, since it uses less digits than its factorization.

21523732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283230 (or 283228 counting only the distinct ones).

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

The square root of 21523732 is about 4639.3676293219. The cubic root of 21523732 is about 278.1671613397.

The spelling of 21523732 in words is "twenty-one million, five hundred twenty-three thousand, seven hundred thirty-two".