205939771 has 12 divisors (see below), whose sum is σ = 212742912. Its totient is φ = 199339056.

The previous prime is 205939763. The next prime is 205939777. The reversal of 205939771 is 177939502.

It is not a de Polignac number, because 205939771 - 2³ = 205939763 is a prime.

It is a super-2 number, since 2×205939771² = 84822378559064882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205939777) 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, 234385 + ... + 235261.

It is an arithmetic number, because the mean of its divisors is an integer number (17728576).

Almost surely, 2^205939771 is an apocalyptic number.

205939771 is a deficient number, since it is larger than the sum of its proper divisors (6803141).

205939771 is an equidigital number, since it uses as much as digits as its factorization.

205939771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090 (or 1047 counting only the distinct ones).

The product of its (nonzero) digits is 119070, while the sum is 43.

The square root of 205939771 is about 14350.6017643860. The cubic root of 205939771 is about 590.5364946784.

The spelling of 205939771 in words is "two hundred five million, nine hundred thirty-nine thousand, seven hundred seventy-one".