21473504 has 48 divisors (see below), whose sum is σ = 46675440. Its totient is φ = 9661440.

The previous prime is 21473497. The next prime is 21473527. The reversal of 21473504 is 40537412.

It is a super-2 number, since 2×21473504² = 922222748076032, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16427 + ... + 17685.

It is an arithmetic number, because the mean of its divisors is an integer number (972405).

Almost surely, 2^21473504 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21473504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23337720).

21473504 is an abundant number, since it is smaller than the sum of its proper divisors (25201936).

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

21473504 is a wasteful number, since it uses less digits than its factorization.

21473504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323 (or 1315 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 21473504 is about 4633.9512297822. The cubic root of 21473504 is about 277.9506149013.

The spelling of 21473504 in words is "twenty-one million, four hundred seventy-three thousand, five hundred four".