205617 has 4 divisors (see below), whose sum is σ = 274160. Its totient is φ = 137076.

The previous prime is 205607. The next prime is 205619. The reversal of 205617 is 716502.

205617 is nontrivially palindromic in base 12.

205617 is an esthetic number in base 12, because in such base its adjacent digits differ by 1.

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 205617 - 2⁶ = 205553 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205593 and 205602.

It is not an unprimeable number, because it can be changed into a prime (205619) 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, 34267 + ... + 34272.

It is an arithmetic number, because the mean of its divisors is an integer number (68540).

2²⁰⁵⁶¹⁷ is an apocalyptic number.

It is an amenable number.

205617 is a deficient number, since it is larger than the sum of its proper divisors (68543).

205617 is an equidigital number, since it uses as much as digits as its factorization.

205617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68542.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 205617 is about 453.4501075091. The cubic root of 205617 is about 59.0227815881.

The spelling of 205617 in words is "two hundred five thousand, six hundred seventeen".