21044441 has 16 divisors (see below), whose sum is σ = 23529408. Its totient is φ = 18817920.

The previous prime is 21044431. The next prime is 21044467. The reversal of 21044441 is 14444012.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21044441 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21044431) 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 15 ways as a sum of consecutive naturals, for example, 129026 + ... + 129188.

It is an arithmetic number, because the mean of its divisors is an integer number (1470588).

Almost surely, 2^21044441 is an apocalyptic number.

It is an amenable number.

21044441 is a deficient number, since it is larger than the sum of its proper divisors (2484967).

21044441 is an equidigital number, since it uses as much as digits as its factorization.

21044441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 21044441 is about 4587.4220429344. The cubic root of 21044441 is about 276.0868985281.

Adding to 21044441 its reverse (14444012), we get a palindrome (35488453).

The spelling of 21044441 in words is "twenty-one million, forty-four thousand, four hundred forty-one".