205291 has 4 divisors (see below), whose sum is σ = 212400. Its totient is φ = 198184.

The previous prime is 205267. The next prime is 205297. The reversal of 205291 is 192502.

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

It is a cyclic number.

It is not a de Polignac number, because 205291 - 2¹⁷ = 74219 is a prime.

It is a Duffinian number.

205291 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (205297) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3511 + ... + 3568.

It is an arithmetic number, because the mean of its divisors is an integer number (53100).

2²⁰⁵²⁹¹ is an apocalyptic number.

205291 is a deficient number, since it is larger than the sum of its proper divisors (7109).

205291 is an equidigital number, since it uses as much as digits as its factorization.

205291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7108.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 205291 is about 453.0904986865. The cubic root of 205291 is about 58.9915720989.

Adding to 205291 its reverse (192502), we get a palindrome (397793).

It can be divided in two parts, 205 and 291, that added together give a triangular number (496 = T₃₁).

The spelling of 205291 in words is "two hundred five thousand, two hundred ninety-one".