205566 has 8 divisors (see below), whose sum is σ = 411144. Its totient is φ = 68520.

The previous prime is 205559. The next prime is 205589. The reversal of 205566 is 665502.

It is a sphenic number, since it is the product of 3 distinct primes.

205566 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17125 + ... + 17136.

It is an arithmetic number, because the mean of its divisors is an integer number (51393).

2²⁰⁵⁵⁶⁶ is an apocalyptic number.

205566 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205566 is a wasteful number, since it uses less digits than its factorization.

205566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34266.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 205566 is about 453.3938685073. The cubic root of 205566 is about 59.0179012998.

The spelling of 205566 in words is "two hundred five thousand, five hundred sixty-six".