208091 has 4 divisors (see below), whose sum is σ = 224112. Its totient is φ = 192072.

The previous prime is 208073. The next prime is 208099. The reversal of 208091 is 190802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190802 = 2 ⋅95401.

It is a cyclic number.

It is not a de Polignac number, because 208091 - 2¹⁴ = 191707 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208099) by changing a digit.

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, 7991 + ... + 8016.

It is an arithmetic number, because the mean of its divisors is an integer number (56028).

2²⁰⁸⁰⁹¹ is an apocalyptic number.

208091 is a deficient number, since it is larger than the sum of its proper divisors (16021).

208091 is a wasteful number, since it uses less digits than its factorization.

208091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16020.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 208091 is about 456.1699244799. The cubic root of 208091 is about 59.2585607219.

Adding to 208091 its reverse (190802), we get a palindrome (398893).

The spelling of 208091 in words is "two hundred eight thousand, ninety-one".