13818 has 24 divisors (see below), whose sum is σ = 32832. Its totient is φ = 3864.

The previous prime is 13807. The next prime is 13829. The reversal of 13818 is 81831.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (13807) and next prime (13829).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nialpdrome in base 7 and base 11.

It is a junction number, because it is equal to n+sod(n) for n = 13794 and 13803.

It is an unprimeable number.

13818 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 11 ways as a sum of consecutive naturals, for example, 271 + ... + 317.

It is an arithmetic number, because the mean of its divisors is an integer number (1368).

It is a practical number, because each smaller number is the sum of distinct divisors of 13818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16416).

13818 is an abundant number, since it is smaller than the sum of its proper divisors (19014).

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

13818 is a wasteful number, since it uses less digits than its factorization.

13818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 59 counting only the distinct ones).

The product of its digits is 192, while the sum is 21.

The square root of 13818 is about 117.5499893662. The cubic root of 13818 is about 23.9965272753.

Multiplying 13818 by its product of digits (192), we get a triangular number (2653056 = T₂₃₀₃).

The spelling of 13818 in words is "thirteen thousand, eight hundred eighteen".