21044804 has 18 divisors (see below), whose sum is σ = 40481742. Its totient is φ = 9565600.

The previous prime is 21044797. The next prime is 21044813. The reversal of 21044804 is 40844012.

It can be written as a sum of positive squares in only one way, i.e., 19360000 + 1684804 = 4400^2 + 1298^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21044804.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21257 + ... + 22224.

Almost surely, 2^21044804 is an apocalyptic number.

It is an amenable number.

21044804 is a deficient number, since it is larger than the sum of its proper divisors (19436938).

21044804 is a wasteful number, since it uses less digits than its factorization.

21044804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43507 (or 43494 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

The square root of 21044804 is about 4587.4616074688. The cubic root of 21044804 is about 276.0884859460.

Adding to 21044804 its reverse (40844012), we get a palindrome (61888816).

The spelling of 21044804 in words is "twenty-one million, forty-four thousand, eight hundred four".