13520521 has 6 divisors (see below), whose sum is σ = 15728010. Its totient is φ = 11588976.

The previous prime is 13520509. The next prime is 13520531. The reversal of 13520521 is 12502531.

13520521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 11148921 + 2371600 = 3339^2 + 1540^2 .

It is not a de Polignac number, because 13520521 - 2¹¹ = 13518473 is a prime.

It is a super-2 number, since 2×13520521² = 365608976222882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13520531) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 137916 + ... + 138013.

It is an arithmetic number, because the mean of its divisors is an integer number (2621335).

Almost surely, 2^13520521 is an apocalyptic number.

It is an amenable number.

13520521 is a deficient number, since it is larger than the sum of its proper divisors (2207489).

13520521 is an equidigital number, since it uses as much as digits as its factorization.

13520521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275943 (or 275936 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 13520521 is about 3677.0261081477. The cubic root of 13520521 is about 238.2307450745.

It can be divided in two parts, 13520 and 521, that added together give a palindrome (14041).

The spelling of 13520521 in words is "thirteen million, five hundred twenty thousand, five hundred twenty-one".