206555761 has 2 divisors, whose sum is σ = 206555762. Its totient is φ = 206555760.

The previous prime is 206555743. The next prime is 206555771. The reversal of 206555761 is 167555602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177395761 + 29160000 = 13319^2 + 5400^2 .

It is a cyclic number.

It is not a de Polignac number, because 206555761 - 2⁷ = 206555633 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 206555761.

It is not a weakly prime, because it can be changed into another prime (206555731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103277880 + 103277881.

It is an arithmetic number, because the mean of its divisors is an integer number (103277881).

Almost surely, 2^206555761 is an apocalyptic number.

It is an amenable number.

206555761 is a deficient number, since it is larger than the sum of its proper divisors (1).

206555761 is an equidigital number, since it uses as much as digits as its factorization.

206555761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63000, while the sum is 37.

The square root of 206555761 is about 14372.0479055700. The cubic root of 206555761 is about 591.1246965712.

The spelling of 206555761 in words is "two hundred six million, five hundred fifty-five thousand, seven hundred sixty-one".