11855 has 4 divisors (see below), whose sum is σ = 14232. Its totient is φ = 9480.

The previous prime is 11839. The next prime is 11863. The reversal of 11855 is 55811.

11855 is nontrivially palindromic in base 7.

11855 is digitally balanced in base 3, 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.

It is not a de Polignac number, because 11855 - 2⁴ = 11839 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1181 + ... + 1190.

It is an arithmetic number, because the mean of its divisors is an integer number (3558).

2¹¹⁸⁵⁵ is an apocalyptic number.

11855 is a deficient number, since it is larger than the sum of its proper divisors (2377).

11855 is an equidigital number, since it uses as much as digits as its factorization.

11855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2376.

The product of its digits is 200, while the sum is 20.

The square root of 11855 is about 108.8806686240. The cubic root of 11855 is about 22.8016978319.

Subtracting 11855 from its reverse (55811), we obtain a triangular number (43956 = T₂₉₆).

The spelling of 11855 in words is "eleven thousand, eight hundred fifty-five".