11820 has 24 divisors (see below), whose sum is σ = 33264. Its totient is φ = 3136.

The previous prime is 11813. The next prime is 11821. The reversal of 11820 is 2811.

It is a happy number.

11820 is nontrivially palindromic in base 14.

11820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (12).

11820 is a nontrivial repdigit in base 14.

It is a plaindrome in base 14.

It is a nialpdrome in base 14.

It is a zygodrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 11796 and 11805.

It is not an unprimeable number, because it can be changed into a prime (11821) by changing a digit.

11820 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 39 + ... + 158.

It is an arithmetic number, because the mean of its divisors is an integer number (1386).

2¹¹⁸²⁰ is an apocalyptic number.

11820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11820 is an abundant number, since it is smaller than the sum of its proper divisors (21444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16632).

11820 is a wasteful number, since it uses less digits than its factorization.

11820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209 (or 207 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 11820 is about 108.7198233994. The cubic root of 11820 is about 22.7792362518.

Subtracting from 11820 its reverse (2811), we obtain a palindrome (9009).

The spelling of 11820 in words is "eleven thousand, eight hundred twenty".