205043239217 has 16 divisors (see below), whose sum is σ = 210494592000. Its totient is φ = 199638969600.

The previous prime is 205043239183. The next prime is 205043239223. The reversal of 205043239217 is 712932340502.

It is a cyclic number.

It is not a de Polignac number, because 205043239217 - 2¹⁰ = 205043238193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205043235217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11774717 + ... + 11792117.

It is an arithmetic number, because the mean of its divisors is an integer number (13155912000).

Almost surely, 2^205043239217 is an apocalyptic number.

It is an amenable number.

205043239217 is a deficient number, since it is larger than the sum of its proper divisors (5451352783).

205043239217 is a wasteful number, since it uses less digits than its factorization.

205043239217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18736.

The product of its (nonzero) digits is 90720, while the sum is 38.

Adding to 205043239217 its reverse (712932340502), we get a palindrome (917975579719).

The spelling of 205043239217 in words is "two hundred five billion, forty-three million, two hundred thirty-nine thousand, two hundred seventeen".