13520 has 30 divisors (see below), whose sum is σ = 34038. Its totient is φ = 4992.

The previous prime is 13513. The next prime is 13523. The reversal of 13520 is 2531.

It can be written as a sum of positive squares in 3 ways, for example, as 64 + 13456 = 8^2 + 116^2 .

It is a hoax number, since the sum of its digits (11) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13523) by changing a digit.

13520 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1034 + ... + 1046.

2¹³⁵²⁰ is an apocalyptic number.

13520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17019).

13520 is an abundant number, since it is smaller than the sum of its proper divisors (20518).

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

13520 is a wasteful number, since it uses less digits than its factorization.

13520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 11.

The square root of 13520 is about 116.2755348300. The cubic root of 13520 is about 23.8227685039.

Adding to 13520 its sum of digits (11), we get a palindrome (13531).

The spelling of 13520 in words is "thirteen thousand, five hundred twenty".