21044305 has 16 divisors (see below), whose sum is σ = 27305280. Its totient is φ = 15515712.

The previous prime is 21044293. The next prime is 21044311. The reversal of 21044305 is 50344012.

It is a cyclic number.

It is not a de Polignac number, because 21044305 - 2⁹ = 21043793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 522 + ... + 6508.

It is an arithmetic number, because the mean of its divisors is an integer number (1706580).

Almost surely, 2^21044305 is an apocalyptic number.

It is an amenable number.

21044305 is a deficient number, since it is larger than the sum of its proper divisors (6260975).

21044305 is a wasteful number, since it uses less digits than its factorization.

21044305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6048.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21044305 is about 4587.4072197702. The cubic root of 21044305 is about 276.0863037883.

Adding to 21044305 its reverse (50344012), we get a palindrome (71388317).

The spelling of 21044305 in words is "twenty-one million, forty-four thousand, three hundred five".