21837872 has 20 divisors (see below), whose sum is σ = 48355536. Its totient is φ = 9359040.

The previous prime is 21837853. The next prime is 21837889. The reversal of 21837872 is 27873812.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97379 + ... + 97602.

Almost surely, 2^21837872 is an apocalyptic number.

It is an amenable number.

21837872 is an abundant number, since it is smaller than the sum of its proper divisors (26517664).

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

21837872 is a wasteful number, since it uses less digits than its factorization.

21837872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194996 (or 194990 counting only the distinct ones).

The product of its digits is 37632, while the sum is 38.

The square root of 21837872 is about 4673.1008976910. The cubic root of 21837872 is about 279.5139185532.

The spelling of 21837872 in words is "twenty-one million, eight hundred thirty-seven thousand, eight hundred seventy-two".