686518229 has 2 divisors, whose sum is σ = 686518230. Its totient is φ = 686518228.

The previous prime is 686518199. The next prime is 686518243. The reversal of 686518229 is 922815686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 404211025 + 282307204 = 20105^2 + 16802^2 .

It is a cyclic number.

It is not a de Polignac number, because 686518229 - 2¹² = 686514133 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686518289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343259114 + 343259115.

It is an arithmetic number, because the mean of its divisors is an integer number (343259115).

Almost surely, 2^686518229 is an apocalyptic number.

It is an amenable number.

686518229 is a deficient number, since it is larger than the sum of its proper divisors (1).

686518229 is an equidigital number, since it uses as much as digits as its factorization.

686518229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 414720, while the sum is 47.

The square root of 686518229 is about 26201.4928773152. The cubic root of 686518229 is about 882.1667632529.

The spelling of 686518229 in words is "six hundred eighty-six million, five hundred eighteen thousand, two hundred twenty-nine".