21089984 has 28 divisors (see below), whose sum is σ = 42062400. Its totient is φ = 10491648.

The previous prime is 21089983. The next prime is 21089987. The reversal of 21089984 is 48998012.

It is not an unprimeable number, because it can be changed into a prime (21089983) 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, 13937 + ... + 15375.

Almost surely, 2^21089984 is an apocalyptic number.

It is an amenable number.

21089984 is a deficient number, since it is larger than the sum of its proper divisors (20972416).

21089984 is a wasteful number, since it uses less digits than its factorization.

21089984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680 (or 1670 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 21089984 is about 4592.3832592675. The cubic root of 21089984 is about 276.2859180859.

The spelling of 21089984 in words is "twenty-one million, eighty-nine thousand, nine hundred eighty-four".