205743 has 4 divisors (see below), whose sum is σ = 274328. Its totient is φ = 137160.

The previous prime is 205721. The next prime is 205759. The reversal of 205743 is 347502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 205743 - 2⁸ = 205487 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205703) by changing a digit.

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, 34288 + ... + 34293.

It is an arithmetic number, because the mean of its divisors is an integer number (68582).

2²⁰⁵⁷⁴³ is an apocalyptic number.

205743 is a deficient number, since it is larger than the sum of its proper divisors (68585).

205743 is an equidigital number, since it uses as much as digits as its factorization.

205743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68584.

The product of its (nonzero) digits is 840, while the sum is 21.

The square root of 205743 is about 453.5890210312. The cubic root of 205743 is about 59.0348353125.

The spelling of 205743 in words is "two hundred five thousand, seven hundred forty-three".