205865089 has 2 divisors, whose sum is σ = 205865090. Its totient is φ = 205865088.

The previous prime is 205865083. The next prime is 205865117. The reversal of 205865089 is 980568502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196224064 + 9641025 = 14008^2 + 3105^2 .

It is a cyclic number.

It is not a de Polignac number, because 205865089 - 2¹⁵ = 205832321 is a prime.

It is not a weakly prime, because it can be changed into another prime (205865083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102932544 + 102932545.

It is an arithmetic number, because the mean of its divisors is an integer number (102932545).

Almost surely, 2^205865089 is an apocalyptic number.

It is an amenable number.

205865089 is a deficient number, since it is larger than the sum of its proper divisors (1).

205865089 is an equidigital number, since it uses as much as digits as its factorization.

205865089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 172800, while the sum is 43.

The square root of 205865089 is about 14347.9994772791. Note that the first 3 decimals coincide. The cubic root of 205865089 is about 590.4651019949.

The spelling of 205865089 in words is "two hundred five million, eight hundred sixty-five thousand, eighty-nine".