21487732 has 24 divisors (see below), whose sum is σ = 43292480. Its totient is φ = 9141120.

The previous prime is 21487717. The next prime is 21487751. The reversal of 21487732 is 23778412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1132 + ... + 6652.

Almost surely, 2^21487732 is an apocalyptic number.

It is an amenable number.

21487732 is an abundant number, since it is smaller than the sum of its proper divisors (21804748).

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

21487732 is a wasteful number, since it uses less digits than its factorization.

21487732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5671 (or 5669 counting only the distinct ones).

The product of its digits is 18816, while the sum is 34.

The square root of 21487732 is about 4635.4861665202. The cubic root of 21487732 is about 278.0119898906.

The spelling of 21487732 in words is "twenty-one million, four hundred eighty-seven thousand, seven hundred thirty-two".