21418872 has 32 divisors (see below), whose sum is σ = 53660880. Its totient is φ = 7124480.

The previous prime is 21418853. The next prime is 21418889. The reversal of 21418872 is 27881412.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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, 20638 + ... + 21650.

Almost surely, 2^21418872 is an apocalyptic number.

It is an amenable number.

21418872 is an abundant number, since it is smaller than the sum of its proper divisors (32242008).

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

21418872 is a wasteful number, since it uses less digits than its factorization.

21418872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1903 (or 1899 counting only the distinct ones).

The product of its digits is 7168, while the sum is 33.

The square root of 21418872 is about 4628.0527222580. The cubic root of 21418872 is about 277.7146979016.

The spelling of 21418872 in words is "twenty-one million, four hundred eighteen thousand, eight hundred seventy-two".