21523984 has 20 divisors (see below), whose sum is σ = 41783040. Its totient is φ = 10741280.

The previous prime is 21523969. The next prime is 21523991. The reversal of 21523984 is 48932512.

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, 10569 + ... + 12439.

It is an arithmetic number, because the mean of its divisors is an integer number (2089152).

Almost surely, 2^21523984 is an apocalyptic number.

It is an amenable number.

21523984 is a deficient number, since it is larger than the sum of its proper divisors (20259056).

21523984 is a wasteful number, since it uses less digits than its factorization.

21523984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2598 (or 2592 counting only the distinct ones).

The product of its digits is 17280, while the sum is 34.

The square root of 21523984 is about 4639.3947881162. The cubic root of 21523984 is about 278.1682469298.

The spelling of 21523984 in words is "twenty-one million, five hundred twenty-three thousand, nine hundred eighty-four".