21221434244 has 12 divisors (see below), whose sum is σ = 37144637964. Its totient is φ = 10608680544.

The previous prime is 21221434187. The next prime is 21221434277. The reversal of 21221434244 is 44243412212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18964044100 + 2257390144 = 137710^2 + 47512^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 485579 + ... + 527474.

It is an arithmetic number, because the mean of its divisors is an integer number (3095386497).

Almost surely, 2^21221434244 is an apocalyptic number.

It is an amenable number.

21221434244 is a deficient number, since it is larger than the sum of its proper divisors (15923203720).

21221434244 is a wasteful number, since it uses less digits than its factorization.

21221434244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1018294 (or 1018292 counting only the distinct ones).

The product of its digits is 12288, while the sum is 29.

Adding to 21221434244 its reverse (44243412212), we get a palindrome (65464846456).

The spelling of 21221434244 in words is "twenty-one billion, two hundred twenty-one million, four hundred thirty-four thousand, two hundred forty-four".