205243 has 4 divisors (see below), whose sum is σ = 206640. Its totient is φ = 203848.

The previous prime is 205237. The next prime is 205253. The reversal of 205243 is 342502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 342502 = 2 ⋅171251.

It is a cyclic number.

It is not a de Polignac number, because 205243 - 2⁵ = 205211 is a prime.

It is a Duffinian number.

205243 is a lucky number.

It is a nialpdrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (205213) 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, 448 + ... + 781.

It is an arithmetic number, because the mean of its divisors is an integer number (51660).

2²⁰⁵²⁴³ is an apocalyptic number.

205243 is a deficient number, since it is larger than the sum of its proper divisors (1397).

205243 is a wasteful number, since it uses less digits than its factorization.

205243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1396.

The product of its (nonzero) digits is 240, while the sum is 16.

The square root of 205243 is about 453.0375260395. The cubic root of 205243 is about 58.9869740467.

Adding to 205243 its reverse (342502), we get a palindrome (547745).

The spelling of 205243 in words is "two hundred five thousand, two hundred forty-three".