21672732 has 12 divisors (see below), whose sum is σ = 50569736. Its totient is φ = 7224240.

The previous prime is 21672719. The next prime is 21672733. The reversal of 21672732 is 23727612.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21672732.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21672733) 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, 903019 + ... + 903042.

Almost surely, 2^21672732 is an apocalyptic number.

It is an amenable number.

21672732 is an abundant number, since it is smaller than the sum of its proper divisors (28897004).

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

21672732 is a wasteful number, since it uses less digits than its factorization.

21672732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806068 (or 1806066 counting only the distinct ones).

The product of its digits is 7056, while the sum is 30.

The square root of 21672732 is about 4655.3981569786. The cubic root of 21672732 is about 278.8075650450.

The spelling of 21672732 in words is "twenty-one million, six hundred seventy-two thousand, seven hundred thirty-two".