21044339 has 4 divisors (see below), whose sum is σ = 21441456. Its totient is φ = 20647224.

The previous prime is 21044311. The next prime is 21044341. The reversal of 21044339 is 93344012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21044339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21044369) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 198479 + ... + 198584.

It is an arithmetic number, because the mean of its divisors is an integer number (5360364).

Almost surely, 2^21044339 is an apocalyptic number.

21044339 is a deficient number, since it is larger than the sum of its proper divisors (397117).

21044339 is an equidigital number, since it uses as much as digits as its factorization.

21044339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397116.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 21044339 is about 4587.4109255657. The cubic root of 21044339 is about 276.0864524735.

The spelling of 21044339 in words is "twenty-one million, forty-four thousand, three hundred thirty-nine".