12811 has 4 divisors (see below), whose sum is σ = 13392. Its totient is φ = 12232.

The previous prime is 12809. The next prime is 12821. The reversal of 12811 is 11821.

12811 is nontrivially palindromic in base 8.

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 12811 - 2¹ = 12809 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12791 and 12800.

It is not an unprimeable number, because it can be changed into a prime (12821) 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, 256 + ... + 301.

It is an arithmetic number, because the mean of its divisors is an integer number (3348).

2¹²⁸¹¹ is an apocalyptic number.

12811 is the 61-st centered heptagonal number.

12811 is a deficient number, since it is larger than the sum of its proper divisors (581).

12811 is an equidigital number, since it uses as much as digits as its factorization.

12811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580.

The product of its digits is 16, while the sum is 13.

The square root of 12811 is about 113.1856881412. The cubic root of 12811 is about 23.3988408611.

Subtracting from 12811 its reverse (11821), we obtain a triangular number (990 = T₄₄).

The spelling of 12811 in words is "twelve thousand, eight hundred eleven".