21513164444 has 12 divisors (see below), whose sum is σ = 37649102568. Its totient is φ = 10756278000.

The previous prime is 21513164443. The next prime is 21513164473. The reversal of 21513164444 is 44446131512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513164443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 175499 + ... + 271709.

It is an arithmetic number, because the mean of its divisors is an integer number (3137425214).

Almost surely, 2^21513164444 is an apocalyptic number.

It is an amenable number.

21513164444 is a deficient number, since it is larger than the sum of its proper divisors (16135938124).

21513164444 is a wasteful number, since it uses less digits than its factorization.

21513164444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152116 (or 152114 counting only the distinct ones).

The product of its digits is 46080, while the sum is 35.

Adding to 21513164444 its reverse (44446131512), we get a palindrome (65959295956).

The spelling of 21513164444 in words is "twenty-one billion, five hundred thirteen million, one hundred sixty-four thousand, four hundred forty-four".