255806209 has 2 divisors, whose sum is σ = 255806210. Its totient is φ = 255806208.

The previous prime is 255806171. The next prime is 255806237. The reversal of 255806209 is 902608552.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 142277184 + 113529025 = 11928^2 + 10655^2 .

It is a cyclic number.

It is not a de Polignac number, because 255806209 - 2⁷ = 255806081 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (255806909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127903104 + 127903105.

It is an arithmetic number, because the mean of its divisors is an integer number (127903105).

Almost surely, 2^255806209 is an apocalyptic number.

It is an amenable number.

255806209 is a deficient number, since it is larger than the sum of its proper divisors (1).

255806209 is an equidigital number, since it uses as much as digits as its factorization.

255806209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 255806209 is about 15993.9428847298. The cubic root of 255806209 is about 634.8001594887.

The spelling of 255806209 in words is "two hundred fifty-five million, eight hundred six thousand, two hundred nine".