206540689 has 2 divisors, whose sum is σ = 206540690. Its totient is φ = 206540688.

The previous prime is 206540641. The next prime is 206540743. The reversal of 206540689 is 986045602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 181710400 + 24830289 = 13480^2 + 4983^2 .

It is a cyclic number.

It is not a de Polignac number, because 206540689 - 2⁷ = 206540561 is a prime.

It is not a weakly prime, because it can be changed into another prime (206546689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103270344 + 103270345.

It is an arithmetic number, because the mean of its divisors is an integer number (103270345).

Almost surely, 2^206540689 is an apocalyptic number.

It is an amenable number.

206540689 is a deficient number, since it is larger than the sum of its proper divisors (1).

206540689 is an equidigital number, since it uses as much as digits as its factorization.

206540689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 206540689 is about 14371.5235448438. The cubic root of 206540689 is about 591.1103184551.

The spelling of 206540689 in words is "two hundred six million, five hundred forty thousand, six hundred eighty-nine".