21139584 has 32 divisors (see below), whose sum is σ = 56153040. Its totient is φ = 7046400.

The previous prime is 21139577. The next prime is 21139589. The reversal of 21139584 is 48593112.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21139589) 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, 27142 + ... + 27909.

Almost surely, 2^21139584 is an apocalyptic number.

21139584 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21139584 is an abundant number, since it is smaller than the sum of its proper divisors (35013456).

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

21139584 is an equidigital number, since it uses as much as digits as its factorization.

21139584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55068 (or 55056 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 21139584 is about 4597.7803340308. The cubic root of 21139584 is about 276.5023407659.

The spelling of 21139584 in words is "twenty-one million, one hundred thirty-nine thousand, five hundred eighty-four".