21056222744 has 8 divisors (see below), whose sum is σ = 39480417660. Its totient is φ = 10528111368.

The previous prime is 21056222743. The next prime is 21056222767. The reversal of 21056222744 is 44722265012.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056222743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1316013914 + ... + 1316013929.

Almost surely, 2^21056222744 is an apocalyptic number.

It is an amenable number.

21056222744 is a deficient number, since it is larger than the sum of its proper divisors (18424194916).

21056222744 is a wasteful number, since it uses less digits than its factorization.

21056222744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2632027849 (or 2632027845 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 35.

Adding to 21056222744 its reverse (44722265012), we get a palindrome (65778487756).

The spelling of 21056222744 in words is "twenty-one billion, fifty-six million, two hundred twenty-two thousand, seven hundred forty-four".