9813 has 4 divisors (see below), whose sum is σ = 13088. Its totient is φ = 6540.

The previous prime is 9811. The next prime is 9817. The reversal of 9813 is 3189.

9813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3189 = 3 ⋅1063.

It is not a de Polignac number, because 9813 - 2¹ = 9811 is a prime.

It is a D-number.

It is a Duffinian number.

9813 is a lucky number.

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 9813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1633 + ... + 1638.

It is an arithmetic number, because the mean of its divisors is an integer number (3272).

2⁹⁸¹³ is an apocalyptic number.

It is an amenable number.

9813 is a deficient number, since it is larger than the sum of its proper divisors (3275).

9813 is a wasteful number, since it uses less digits than its factorization.

9813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3274.

The product of its digits is 216, while the sum is 21.

The square root of 9813 is about 99.0605875210. The cubic root of 9813 is about 21.4092079046.

It can be divided in two parts, 98 and 13, that added together give a palindrome (111).

The spelling of 9813 in words is "nine thousand, eight hundred thirteen".