13131521 has 16 divisors (see below), whose sum is σ = 14732928. Its totient is φ = 11625600.

The previous prime is 13131511. The next prime is 13131523. The reversal of 13131521 is 12513131.

13131521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13131521 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13131521.

It is not an unprimeable number, because it can be changed into a prime (13131523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37670 + ... + 38016.

It is an arithmetic number, because the mean of its divisors is an integer number (920808).

Almost surely, 2^13131521 is an apocalyptic number.

It is an amenable number.

13131521 is a deficient number, since it is larger than the sum of its proper divisors (1601407).

13131521 is a wasteful number, since it uses less digits than its factorization.

13131521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472.

The product of its digits is 90, while the sum is 17.

The square root of 13131521 is about 3623.7440582911. The cubic root of 13131521 is about 235.9237580494.

Adding to 13131521 its reverse (12513131), we get a palindrome (25644652).

The spelling of 13131521 in words is "thirteen million, one hundred thirty-one thousand, five hundred twenty-one".