205306 has 4 divisors (see below), whose sum is σ = 307962. Its totient is φ = 102652.

The previous prime is 205297. The next prime is 205307. The reversal of 205306 is 603502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 603502 = 2 ⋅301751.

It can be written as a sum of positive squares in only one way, i.e., 167281 + 38025 = 409^2 + 195^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 205306.

It is not an unprimeable number, because it can be changed into a prime (205307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51325 + ... + 51328.

2²⁰⁵³⁰⁶ is an apocalyptic number.

205306 is a deficient number, since it is larger than the sum of its proper divisors (102656).

205306 is a wasteful number, since it uses less digits than its factorization.

205306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102655.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 205306 is about 453.1070513687. The cubic root of 205306 is about 58.9930088432.

Adding to 205306 its reverse (603502), we get a palindrome (808808).

The spelling of 205306 in words is "two hundred five thousand, three hundred six".