21220224444 has 36 divisors (see below), whose sum is σ = 54319006560. Its totient is φ = 6983870400.

The previous prime is 21220224427. The next prime is 21220224451. The reversal of 21220224444 is 44442202212.

21220224444 is a `hidden beast` number, since 2 + 12 + 202 + 2 + 4 + 444 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3727857 + ... + 3733544.

Almost surely, 2^21220224444 is an apocalyptic number.

It is an amenable number.

21220224444 is an abundant number, since it is smaller than the sum of its proper divisors (33098782116).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21220224444 is a wasteful number, since it uses less digits than its factorization.

21220224444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7461490 (or 7461485 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 27.

Adding to 21220224444 its reverse (44442202212), we get a palindrome (65662426656).

The spelling of 21220224444 in words is "twenty-one billion, two hundred twenty million, two hundred twenty-four thousand, four hundred forty-four".