91855 has 4 divisors (see below), whose sum is σ = 110232. Its totient is φ = 73480.

The previous prime is 91841. The next prime is 91867. The reversal of 91855 is 55819.

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

It is not a de Polignac number, because 91855 - 2⁵ = 91823 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9181 + ... + 9190.

It is an arithmetic number, because the mean of its divisors is an integer number (27558).

2⁹¹⁸⁵⁵ is an apocalyptic number.

91855 is a deficient number, since it is larger than the sum of its proper divisors (18377).

91855 is a wasteful number, since it uses less digits than its factorization.

91855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18376.

The product of its digits is 1800, while the sum is 28.

The square root of 91855 is about 303.0758980850. The cubic root of 91855 is about 45.1198451510.

It can be divided in two parts, 91 and 855, that added together give a triangular number (946 = T₄₃).

The spelling of 91855 in words is "ninety-one thousand, eight hundred fifty-five".