13531 has 4 divisors (see below), whose sum is σ = 15472.
Its totient is φ = 11592.
The previous prime is 13523. The next prime is 13537.
It can be divided in two parts, 13 and 531, that multiplied together give a triangular number (6903 = T117).
13531 is nontrivially palindromic in base 10.
It is a semiprime because it is the product of two primes.
It is not a de Polignac number, because 13531 - 23 = 13523 is a prime.
It is a super-2 number, since 2×135312 = 366175922, which contains 22 as substring.
It is an Ulam number.
It is a pancake number, because a pancake can be divided into 13531 parts by 164 straight cuts.
It is a Duffinian number.
13531 is a lucky number.
It is a nialpdrome in base 7.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (13537) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 960 + ... + 973.
It is an arithmetic number, because the mean of its divisors is an integer number (3868).
213531 is an apocalyptic number.
13531 is a deficient number, since it is larger than the sum of its proper divisors (1941).
13531 is an equidigital number, since it uses as much as digits as its factorization.
13531 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1940.
The product of its digits is 45, while the sum is 13.
The square root of 13531 is about 116.3228266507.
The cubic root of 13531 is about 23.8292275625.
The spelling of 13531 in words is "thirteen thousand, five hundred thirty-one".