205989717 has 4 divisors (see below), whose sum is σ = 274652960. Its totient is φ = 137326476.

The previous prime is 205989713. The next prime is 205989727. The reversal of 205989717 is 717989502.

205989717 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 205989717 - 2² = 205989713 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205989713) 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, 34331617 + ... + 34331622.

It is an arithmetic number, because the mean of its divisors is an integer number (68663240).

Almost surely, 2^205989717 is an apocalyptic number.

It is an amenable number.

205989717 is a deficient number, since it is larger than the sum of its proper divisors (68663243).

205989717 is an equidigital number, since it uses as much as digits as its factorization.

205989717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68663242.

The product of its (nonzero) digits is 317520, while the sum is 48.

The square root of 205989717 is about 14352.3418646575. The cubic root of 205989717 is about 590.5842312107.

The spelling of 205989717 in words is "two hundred five million, nine hundred eighty-nine thousand, seven hundred seventeen".