208191 has 8 divisors (see below), whose sum is σ = 287280. Its totient is φ = 133952.

The previous prime is 208189. The next prime is 208207. The reversal of 208191 is 191802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 208191 - 2¹ = 208189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1110 + ... + 1283.

It is an arithmetic number, because the mean of its divisors is an integer number (35910).

2²⁰⁸¹⁹¹ is an apocalyptic number.

208191 is a deficient number, since it is larger than the sum of its proper divisors (79089).

208191 is a wasteful number, since it uses less digits than its factorization.

208191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2425.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 208191 is about 456.2795195930. The cubic root of 208191 is about 59.2680516130.

Adding to 208191 its product of nonzero digits (144), we get a triangular number (208335 = T₆₄₅).

Adding to 208191 its reverse (191802), we get a palindrome (399993).

The spelling of 208191 in words is "two hundred eight thousand, one hundred ninety-one".