21637672 has 32 divisors (see below), whose sum is σ = 47358720. Its totient is φ = 9074880.

The previous prime is 21637669. The next prime is 21637673. The reversal of 21637672 is 27673612.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21637673) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1479 + ... + 6742.

It is an arithmetic number, because the mean of its divisors is an integer number (1479960).

Almost surely, 2^21637672 is an apocalyptic number.

It is an amenable number.

21637672 is an abundant number, since it is smaller than the sum of its proper divisors (25721048).

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

21637672 is a wasteful number, since it uses less digits than its factorization.

21637672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8281 (or 8277 counting only the distinct ones).

The product of its digits is 21168, while the sum is 34.

The square root of 21637672 is about 4651.6311117714. The cubic root of 21637672 is about 278.6571414777.

The spelling of 21637672 in words is "twenty-one million, six hundred thirty-seven thousand, six hundred seventy-two".