21104808 has 32 divisors (see below), whose sum is σ = 54583200. Its totient is φ = 6792128.

The previous prime is 21104773. The next prime is 21104819. The reversal of 21104808 is 80840112.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 14466 + ... + 15857.

It is an arithmetic number, because the mean of its divisors is an integer number (1705725).

Almost surely, 2^21104808 is an apocalyptic number.

It is an amenable number.

21104808 is an abundant number, since it is smaller than the sum of its proper divisors (33478392).

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

21104808 is a wasteful number, since it uses less digits than its factorization.

21104808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30361 (or 30357 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 21104808 is about 4593.9969525458. The cubic root of 21104808 is about 276.3506360616.

It can be divided in two parts, 21104 and 808, that added together give a palindrome (21912).

The spelling of 21104808 in words is "twenty-one million, one hundred four thousand, eight hundred eight".