205889689 has 2 divisors, whose sum is σ = 205889690. Its totient is φ = 205889688.

The previous prime is 205889653. The next prime is 205889699. The reversal of 205889689 is 986988502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144000000 + 61889689 = 12000^2 + 7867^2 .

It is a cyclic number.

It is not a de Polignac number, because 205889689 - 2⁷ = 205889561 is a prime.

It is not a weakly prime, because it can be changed into another prime (205889699) 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, 102944844 + 102944845.

It is an arithmetic number, because the mean of its divisors is an integer number (102944845).

Almost surely, 2^205889689 is an apocalyptic number.

It is an amenable number.

205889689 is a deficient number, since it is larger than the sum of its proper divisors (1).

205889689 is an equidigital number, since it uses as much as digits as its factorization.

205889689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2488320, while the sum is 55.

The square root of 205889689 is about 14348.8567140382. The cubic root of 205889689 is about 590.4886204118.

The spelling of 205889689 in words is "two hundred five million, eight hundred eighty-nine thousand, six hundred eighty-nine".