205655761 has 2 divisors, whose sum is σ = 205655762. Its totient is φ = 205655760.

The previous prime is 205655707. The next prime is 205655777. The reversal of 205655761 is 167556502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204347025 + 1308736 = 14295^2 + 1144^2 .

It is a cyclic number.

It is not a de Polignac number, because 205655761 - 2¹³ = 205647569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205655761.

It is not a weakly prime, because it can be changed into another prime (205655161) 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 as a sum of consecutive naturals, namely, 102827880 + 102827881.

It is an arithmetic number, because the mean of its divisors is an integer number (102827881).

Almost surely, 2^205655761 is an apocalyptic number.

It is an amenable number.

205655761 is a deficient number, since it is larger than the sum of its proper divisors (1).

205655761 is an equidigital number, since it uses as much as digits as its factorization.

205655761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63000, while the sum is 37.

The square root of 205655761 is about 14340.7029465086. The cubic root of 205655761 is about 590.2649016331.

The spelling of 205655761 in words is "two hundred five million, six hundred fifty-five thousand, seven hundred sixty-one".