205966 has 4 divisors (see below), whose sum is σ = 308952. Its totient is φ = 102982.

The previous prime is 205963. The next prime is 205967. The reversal of 205966 is 669502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 669502 = 2 ⋅334751.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51490 + ... + 51493.

It is an arithmetic number, because the mean of its divisors is an integer number (77238).

2²⁰⁵⁹⁶⁶ is an apocalyptic number.

205966 is a deficient number, since it is larger than the sum of its proper divisors (102986).

205966 is a wasteful number, since it uses less digits than its factorization.

205966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102985.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 205966 is about 453.8347716956. The cubic root of 205966 is about 59.0561564345.

It can be divided in two parts, 20596 and 6, that added together give a palindrome (20602).

The spelling of 205966 in words is "two hundred five thousand, nine hundred sixty-six".