13813 has 4 divisors (see below), whose sum is σ = 14560. Its totient is φ = 13068.

The previous prime is 13807. The next prime is 13829. The reversal of 13813 is 31831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31831 = 139 ⋅229.

It is a cyclic number.

It is not a de Polignac number, because 13813 - 2⁵ = 13781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13873) 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, 345 + ... + 382.

It is an arithmetic number, because the mean of its divisors is an integer number (3640).

13813 is a Friedman number, since it can be written as (8*3)^3-11, using all its digits and the basic arithmetic operations.

2¹³⁸¹³ is an apocalyptic number.

It is an amenable number.

13813 is a deficient number, since it is larger than the sum of its proper divisors (747).

13813 is an equidigital number, since it uses as much as digits as its factorization.

13813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746.

The product of its digits is 72, while the sum is 16.

The square root of 13813 is about 117.5287198943. The cubic root of 13813 is about 23.9936325701.

It can be divided in two parts, 138 and 13, that added together give a palindrome (151).

The spelling of 13813 in words is "thirteen thousand, eight hundred thirteen".