206655611509 has 2 divisors, whose sum is σ = 206655611510. Its totient is φ = 206655611508.

The previous prime is 206655611483. The next prime is 206655611549. The reversal of 206655611509 is 905116556602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204353723025 + 2301888484 = 452055^2 + 47978^2 .

It is a cyclic number.

It is not a de Polignac number, because 206655611509 - 2²¹ = 206653514357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206655611549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103327805754 + 103327805755.

It is an arithmetic number, because the mean of its divisors is an integer number (103327805755).

Almost surely, 2^206655611509 is an apocalyptic number.

It is an amenable number.

206655611509 is a deficient number, since it is larger than the sum of its proper divisors (1).

206655611509 is an equidigital number, since it uses as much as digits as its factorization.

206655611509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486000, while the sum is 46.

The spelling of 206655611509 in words is "two hundred six billion, six hundred fifty-five million, six hundred eleven thousand, five hundred nine".