21373504 has 28 divisors (see below), whose sum is σ = 42560748. Its totient is φ = 10649600.

The previous prime is 21373501. The next prime is 21373511. The reversal of 21373504 is 40537312.

It can be written as a sum of positive squares in 2 ways, for example, as 13307904 + 8065600 = 3648^2 + 2840^2 .

It is not an unprimeable number, because it can be changed into a prime (21373501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33024 + ... + 33664.

Almost surely, 2^21373504 is an apocalyptic number.

It is an amenable number.

21373504 is a deficient number, since it is larger than the sum of its proper divisors (21187244).

21373504 is an equidigital number, since it uses as much as digits as its factorization.

21373504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1174 (or 1164 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21373504 is about 4623.1487105651. The cubic root of 21373504 is about 277.5184804942.

The spelling of 21373504 in words is "twenty-one million, three hundred seventy-three thousand, five hundred four".