205540189 has 2 divisors, whose sum is σ = 205540190. Its totient is φ = 205540188.

The previous prime is 205540163. The next prime is 205540193. The reversal of 205540189 is 981045502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 105740089 + 99800100 = 10283^2 + 9990^2 .

It is a cyclic number.

It is not a de Polignac number, because 205540189 - 2⁷ = 205540061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205540289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102770094 + 102770095.

It is an arithmetic number, because the mean of its divisors is an integer number (102770095).

Almost surely, 2^205540189 is an apocalyptic number.

It is an amenable number.

205540189 is a deficient number, since it is larger than the sum of its proper divisors (1).

205540189 is an equidigital number, since it uses as much as digits as its factorization.

205540189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 205540189 is about 14336.6728706489. The cubic root of 205540189 is about 590.1543108775.

The spelling of 205540189 in words is "two hundred five million, five hundred forty thousand, one hundred eighty-nine".