204391 has 8 divisors (see below), whose sum is σ = 236304. Its totient is φ = 174720.

The previous prime is 204377. The next prime is 204397. The reversal of 204391 is 193402.

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 204391 - 2⁵ = 204359 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204397) 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 7 ways as a sum of consecutive naturals, for example, 360 + ... + 733.

It is an arithmetic number, because the mean of its divisors is an integer number (29538).

2²⁰⁴³⁹¹ is an apocalyptic number.

204391 is a deficient number, since it is larger than the sum of its proper divisors (31913).

204391 is a wasteful number, since it uses less digits than its factorization.

204391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1121.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 204391 is about 452.0962286947. The cubic root of 204391 is about 58.9052390554.

Adding to 204391 its reverse (193402), we get a palindrome (397793).

It can be divided in two parts, 204 and 391, that added together give a palindrome (595).

The spelling of 204391 in words is "two hundred four thousand, three hundred ninety-one".