191855 has 4 divisors (see below), whose sum is σ = 230232. Its totient is φ = 153480.

The previous prime is 191837. The next prime is 191861. The reversal of 191855 is 558191.

191855 = 65² + 66² + ... + 94².

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 558191 = 131 ⋅4261.

It is not a de Polignac number, because 191855 - 2⁶ = 191791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19181 + ... + 19190.

It is an arithmetic number, because the mean of its divisors is an integer number (57558).

2¹⁹¹⁸⁵⁵ is an apocalyptic number.

191855 is a deficient number, since it is larger than the sum of its proper divisors (38377).

191855 is an equidigital number, since it uses as much as digits as its factorization.

191855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38376.

The product of its digits is 1800, while the sum is 29.

The square root of 191855 is about 438.0125568976. The cubic root of 191855 is about 57.6754565030.

It can be divided in two parts, 19 and 1855, that multiplied together give a triangular number (35245 = T₂₆₅).

The spelling of 191855 in words is "one hundred ninety-one thousand, eight hundred fifty-five".