205005771 has 12 divisors (see below), whose sum is σ = 313538472. Its totient is φ = 128630976.

The previous prime is 205005719. The next prime is 205005791. The reversal of 205005771 is 177500502.

It is not a de Polignac number, because 205005771 - 2¹¹ = 205003723 is a prime.

It is a super-2 number, since 2×205005771² = 84054732286608882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (205005791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 669801 + ... + 670106.

It is an arithmetic number, because the mean of its divisors is an integer number (26128206).

Almost surely, 2^205005771 is an apocalyptic number.

205005771 is a deficient number, since it is larger than the sum of its proper divisors (108532701).

205005771 is a wasteful number, since it uses less digits than its factorization.

205005771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1339930 (or 1339927 counting only the distinct ones).

The product of its (nonzero) digits is 2450, while the sum is 27.

The square root of 205005771 is about 14318.0225939199. The cubic root of 205005771 is about 589.6423869440.

The spelling of 205005771 in words is "two hundred five million, five thousand, seven hundred seventy-one".