9818 has 4 divisors (see below), whose sum is σ = 14730. Its totient is φ = 4908.

The previous prime is 9817. The next prime is 9829. The reversal of 9818 is 8189.

9818 is nontrivially palindromic in base 8.

9818 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 an emirpimes, since its reverse is a distinct semiprime: 8189 = 19 ⋅431.

It can be written as a sum of positive squares in only one way, i.e., 5329 + 4489 = 73^2 + 67^2 .

It is an alternating number because its digits alternate between odd and even.

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 as a sum of consecutive naturals, namely, 2453 + ... + 2456.

2⁹⁸¹⁸ is an apocalyptic number.

9818 is a deficient number, since it is larger than the sum of its proper divisors (4912).

9818 is a wasteful number, since it uses less digits than its factorization.

9818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4911.

The product of its digits is 576, while the sum is 26.

The square root of 9818 is about 99.0858213873. The cubic root of 9818 is about 21.4128434854.

It can be divided in two parts, 981 and 8, that added together give a palindrome (989).

The spelling of 9818 in words is "nine thousand, eight hundred eighteen".