21872208 has 40 divisors (see below), whose sum is σ = 57822688. Its totient is φ = 7120512.

The previous prime is 21872203. The next prime is 21872209. The reversal of 21872208 is 80227812.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21872203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3235 + ... + 7362.

Almost surely, 2^21872208 is an apocalyptic number.

It is an amenable number.

21872208 is an abundant number, since it is smaller than the sum of its proper divisors (35950480).

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

21872208 is a wasteful number, since it uses less digits than its factorization.

21872208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10651 (or 10645 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 21872208 is about 4676.7732465879. The cubic root of 21872208 is about 279.6603364254.

The spelling of 21872208 in words is "twenty-one million, eight hundred seventy-two thousand, two hundred eight".