205669 has 4 divisors (see below), whose sum is σ = 210496. Its totient is φ = 200844.

The previous prime is 205663. The next prime is 205703. The reversal of 205669 is 966502.

205669 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, and also an emirpimes, since its reverse is a distinct semiprime: 966502 = 2 ⋅483251.

It is a cyclic number.

It is not a de Polignac number, because 205669 - 2³ = 205661 is a prime.

It is a super-2 number, since 2×205669² = 84599475122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205661) 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, 2349 + ... + 2434.

It is an arithmetic number, because the mean of its divisors is an integer number (52624).

2²⁰⁵⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

205669 is a deficient number, since it is larger than the sum of its proper divisors (4827).

205669 is an equidigital number, since it uses as much as digits as its factorization.

205669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4826.

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

The square root of 205669 is about 453.5074420558. The cubic root of 205669 is about 59.0277567377.

The spelling of 205669 in words is "two hundred five thousand, six hundred sixty-nine".