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 a Duffinian number.
It is a plaindrome in base 14.
It is a congruent number.
It is an unprimeable number.
211855 is an apocalyptic number.
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 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".