21313116544 has 96 divisors (see below), whose sum is σ = 44967220200. Its totient is φ = 10060775424.

The previous prime is 21313116523. The next prime is 21313116581. The reversal of 21313116544 is 44561131312.

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, 17512224 + ... + 17513440.

Almost surely, 2^21313116544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21313116544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22483610100).

21313116544 is an abundant number, since it is smaller than the sum of its proper divisors (23654103656).

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

21313116544 is a wasteful number, since it uses less digits than its factorization.

21313116544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648 (or 1617 counting only the distinct ones).

The product of its digits is 8640, while the sum is 31.

Adding to 21313116544 its reverse (44561131312), we get a palindrome (65874247856).

The spelling of 21313116544 in words is "twenty-one billion, three hundred thirteen million, one hundred sixteen thousand, five hundred forty-four".