21221120444 has 24 divisors (see below), whose sum is σ = 39104125200. Its totient is φ = 10048872960.

The previous prime is 21221120443. The next prime is 21221120467. The reversal of 21221120444 is 44402112212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221120441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 201452 + ... + 288140.

It is an arithmetic number, because the mean of its divisors is an integer number (1629338550).

Almost surely, 2^21221120444 is an apocalyptic number.

It is an amenable number.

21221120444 is a deficient number, since it is larger than the sum of its proper divisors (17883004756).

21221120444 is a wasteful number, since it uses less digits than its factorization.

21221120444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89933 (or 89931 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 21221120444 its reverse (44402112212), we get a palindrome (65623232656).

The spelling of 21221120444 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty thousand, four hundred forty-four".