205290161 has 2 divisors, whose sum is σ = 205290162. Its totient is φ = 205290160.

The previous prime is 205290149. The next prime is 205290209. The reversal of 205290161 is 161092502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203205025 + 2085136 = 14255^2 + 1444^2 .

It is a cyclic number.

It is not a de Polignac number, because 205290161 - 2¹⁰ = 205289137 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205290161.

It is not a weakly prime, because it can be changed into another prime (205290061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102645080 + 102645081.

It is an arithmetic number, because the mean of its divisors is an integer number (102645081).

Almost surely, 2^205290161 is an apocalyptic number.

It is an amenable number.

205290161 is a deficient number, since it is larger than the sum of its proper divisors (1).

205290161 is an equidigital number, since it uses as much as digits as its factorization.

205290161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 205290161 is about 14327.9503419017. The cubic root of 205290161 is about 589.9149173489.

The spelling of 205290161 in words is "two hundred five million, two hundred ninety thousand, one hundred sixty-one".