6813 has 6 divisors (see below), whose sum is σ = 9854. Its totient is φ = 4536.

The previous prime is 6803. The next prime is 6823. The reversal of 6813 is 3186.

It is an interprime number because it is at equal distance from previous prime (6803) and next prime (6823).

It can be written as a sum of positive squares in only one way, i.e., 6084 + 729 = 78^2 + 27^2 .

It is not a de Polignac number, because 6813 - 2⁵ = 6781 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6803) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 370 + ... + 387.

2⁶⁸¹³ is an apocalyptic number.

It is an amenable number.

6813 is a deficient number, since it is larger than the sum of its proper divisors (3041).

6813 is a wasteful number, since it uses less digits than its factorization.

6813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 763 (or 760 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 6813 is about 82.5408989532. The cubic root of 6813 is about 18.9574300848.

Adding to 6813 its reverse (3186), we get a palindrome (9999).

It can be divided in two parts, 68 and 13, that added together give a 4-th power (81 = 3⁴).

The spelling of 6813 in words is "six thousand, eight hundred thirteen".