205917 has 4 divisors (see below), whose sum is σ = 274560. Its totient is φ = 137276.

The previous prime is 205913. The next prime is 205937. The reversal of 205917 is 719502.

205917 is nontrivially palindromic in base 12.

205917 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 a cyclic number.

It is not a de Polignac number, because 205917 - 2² = 205913 is a prime.

It is a D-number.

205917 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 205917.

It is not an unprimeable number, because it can be changed into a prime (205913) 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, 34317 + ... + 34322.

It is an arithmetic number, because the mean of its divisors is an integer number (68640).

2²⁰⁵⁹¹⁷ is an apocalyptic number.

It is an amenable number.

205917 is a deficient number, since it is larger than the sum of its proper divisors (68643).

205917 is an equidigital number, since it uses as much as digits as its factorization.

205917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68642.

The product of its (nonzero) digits is 630, while the sum is 24.

The square root of 205917 is about 453.7807840797. The cubic root of 205917 is about 59.0514728440.

The spelling of 205917 in words is "two hundred five thousand, nine hundred seventeen".