21044911 has 2 divisors, whose sum is σ = 21044912. Its totient is φ = 21044910.

The previous prime is 21044879. The next prime is 21044917. The reversal of 21044911 is 11944012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21044911 - 2⁵ = 21044879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21044917) by changing a digit.

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 as a sum of consecutive naturals, namely, 10522455 + 10522456.

It is an arithmetic number, because the mean of its divisors is an integer number (10522456).

Almost surely, 2^21044911 is an apocalyptic number.

21044911 is a deficient number, since it is larger than the sum of its proper divisors (1).

21044911 is an equidigital number, since it uses as much as digits as its factorization.

21044911 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 21044911 is about 4587.4732696769. The cubic root of 21044911 is about 276.0889538591.

Adding to 21044911 its reverse (11944012), we get a palindrome (32988923).

The spelling of 21044911 in words is "twenty-one million, forty-four thousand, nine hundred eleven".