243205 has 8 divisors (see below), whose sum is σ = 294912. Its totient is φ = 192528.

The previous prime is 243203. The next prime is 243209. The reversal of 243205 is 502342.

243205 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 243205 - 2¹ = 243203 is a prime.

It is a Duffinian number.

243205 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243203) 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, 444 + ... + 826.

It is an arithmetic number, because the mean of its divisors is an integer number (36864).

2²⁴³²⁰⁵ is an apocalyptic number.

It is an amenable number.

243205 is a deficient number, since it is larger than the sum of its proper divisors (51707).

243205 is a wasteful number, since it uses less digits than its factorization.

243205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515.

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

The square root of 243205 is about 493.1581896309. The cubic root of 243205 is about 62.4200577915.

Adding to 243205 its reverse (502342), we get a palindrome (745547).

The spelling of 243205 in words is "two hundred forty-three thousand, two hundred five".