11665 has 4 divisors (see below), whose sum is σ = 14004. Its totient is φ = 9328.

The previous prime is 11657. The next prime is 11677. The reversal of 11665 is 56611.

11665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 108²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4096 + 7569 = 64^2 + 87^2 .

It is a cyclic number.

It is not a de Polignac number, because 11665 - 2³ = 11657 is a prime.

It is a Duffinian number.

It is an unprimeable 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 3 ways as a sum of consecutive naturals, for example, 1162 + ... + 1171.

It is an arithmetic number, because the mean of its divisors is an integer number (3501).

11665 is a Friedman number, since it can be written as 1+6^6/(5-1), using all its digits and the basic arithmetic operations.

2¹¹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

11665 is a deficient number, since it is larger than the sum of its proper divisors (2339).

11665 is an equidigital number, since it uses as much as digits as its factorization.

11665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2338.

The product of its digits is 180, while the sum is 19.

The square root of 11665 is about 108.0046295304. The cubic root of 11665 is about 22.6792269871.

It can be divided in two parts, 116 and 65, that added together give a palindrome (181).

The spelling of 11665 in words is "eleven thousand, six hundred sixty-five".