13817 has 4 divisors (see below), whose sum is σ = 14196. Its totient is φ = 13440.

The previous prime is 13807. The next prime is 13829. The reversal of 13817 is 71831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71831 = 109 ⋅659.

It can be written as a sum of positive squares in 2 ways, for example, as 1936 + 11881 = 44^2 + 109^2 .

It is a cyclic number.

It is not a de Polignac number, because 13817 - 2¹² = 9721 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (13807) 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, 128 + ... + 209.

It is an arithmetic number, because the mean of its divisors is an integer number (3549).

2¹³⁸¹⁷ is an apocalyptic number.

It is an amenable number.

13817 is a deficient number, since it is larger than the sum of its proper divisors (379).

13817 is an equidigital number, since it uses as much as digits as its factorization.

13817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378.

The product of its digits is 168, while the sum is 20.

The square root of 13817 is about 117.5457357797. The cubic root of 13817 is about 23.9959483901.

It can be divided in two parts, 138 and 17, that multiplied together give a triangular number (2346 = T₆₈).

The spelling of 13817 in words is "thirteen thousand, eight hundred seventeen".