21044605 has 8 divisors (see below), whose sum is σ = 25306200. Its totient is φ = 16800576.

The previous prime is 21044581. The next prime is 21044627. The reversal of 21044605 is 50644012.

It can be written as a sum of positive squares in 4 ways, for example, as 9572836 + 11471769 = 3094^2 + 3387^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21044605 - 2⁷ = 21044477 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1590 + ... + 6679.

It is an arithmetic number, because the mean of its divisors is an integer number (3163275).

Almost surely, 2^21044605 is an apocalyptic number.

It is an amenable number.

21044605 is a deficient number, since it is larger than the sum of its proper divisors (4261595).

21044605 is an equidigital number, since it uses as much as digits as its factorization.

21044605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8783.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21044605 is about 4587.4399178627. The cubic root of 21044605 is about 276.0876157109.

Adding to 21044605 its reverse (50644012), we get a palindrome (71688617).

The spelling of 21044605 in words is "twenty-one million, forty-four thousand, six hundred five".