13811 has 4 divisors (see below), whose sum is σ = 15792. Its totient is φ = 11832.

The previous prime is 13807. The next prime is 13829. The reversal of 13811 is 11831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 13811 - 2² = 13807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13831) 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, 980 + ... + 993.

It is an arithmetic number, because the mean of its divisors is an integer number (3948).

2¹³⁸¹¹ is an apocalyptic number.

13811 is a deficient number, since it is larger than the sum of its proper divisors (1981).

13811 is an equidigital number, since it uses as much as digits as its factorization.

13811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1980.

The product of its digits is 24, while the sum is 14.

The square root of 13811 is about 117.5202110277. The cubic root of 13811 is about 23.9924744924.

The spelling of 13811 in words is "thirteen thousand, eight hundred eleven".