13581338521 has 3 divisors (see below), whose sum is σ = 13581455061. Its totient is φ = 13581221982.

The previous prime is 13581338497. The next prime is 13581338543. The reversal of 13581338521 is 12583318531.

The square root of 13581338521 is 116539.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 13581338521 - 2²⁹ = 13044467609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13581338821) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 58270 + ... + 174808.

It is an arithmetic number, because the mean of its divisors is an integer number (4527151687).

Almost surely, 2^13581338521 is an apocalyptic number.

13581338521 is the 116539-th square number.

13581338521 is the 58270-th centered octagonal number.

It is an amenable number.

13581338521 is a deficient number, since it is larger than the sum of its proper divisors (116540).

13581338521 is an frugal number, since it uses more digits than its factorization.

13581338521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233078 (or 116539 counting only the distinct ones).

The product of its digits is 86400, while the sum is 40.

The spelling of 13581338521 in words is "thirteen billion, five hundred eighty-one million, three hundred thirty-eight thousand, five hundred twenty-one".