11181 has 4 divisors (see below), whose sum is σ = 14912. Its totient is φ = 7452.

The previous prime is 11177. The next prime is 11197. The reversal of 11181 is 18111.

It is a happy number.

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: 18111 = 3 ⋅6037.

It is not a de Polignac number, because 11181 - 2² = 11177 is a prime.

It is a super-2 number, since 2×11181² = 250029522, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

11181 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11131) 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, 1861 + ... + 1866.

It is an arithmetic number, because the mean of its divisors is an integer number (3728).

2¹¹¹⁸¹ is an apocalyptic number.

It is an amenable number.

11181 is a deficient number, since it is larger than the sum of its proper divisors (3731).

11181 is an equidigital number, since it uses as much as digits as its factorization.

11181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3730.

The product of its digits is 8, while the sum is 12.

The square root of 11181 is about 105.7402477773. The cubic root of 11181 is about 22.3611198413.

Adding to 11181 its reverse (18111), we get a palindrome (29292).

It can be divided in two parts, 11 and 181, that multiplied together give a palindrome (1991).

The spelling of 11181 in words is "eleven thousand, one hundred eighty-one".