205771 has 4 divisors (see below), whose sum is σ = 206712. Its totient is φ = 204832.

The previous prime is 205763. The next prime is 205783. The reversal of 205771 is 177502.

205771 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 205771 - 2³ = 205763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205721) 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, 51 + ... + 643.

It is an arithmetic number, because the mean of its divisors is an integer number (51678).

2²⁰⁵⁷⁷¹ is an apocalyptic number.

205771 is a deficient number, since it is larger than the sum of its proper divisors (941).

205771 is an equidigital number, since it uses as much as digits as its factorization.

205771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940.

The product of its (nonzero) digits is 490, while the sum is 22.

The square root of 205771 is about 453.6198849257. The cubic root of 205771 is about 59.0375132495.

The spelling of 205771 in words is "two hundred five thousand, seven hundred seventy-one".