686000009 has 2 divisors, whose sum is σ = 686000010. Its totient is φ = 686000008.

The previous prime is 685999999. The next prime is 686000011. The reversal of 686000009 is 900000686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 657409600 + 28590409 = 25640^2 + 5347^2 .

It is a cyclic number.

It is not a de Polignac number, because 686000009 - 2⁸ = 685999753 is a prime.

Together with 686000011, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (686000089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343000004 + 343000005.

It is an arithmetic number, because the mean of its divisors is an integer number (343000005).

Almost surely, 2^686000009 is an apocalyptic number.

It is an amenable number.

686000009 is a deficient number, since it is larger than the sum of its proper divisors (1).

686000009 is an equidigital number, since it uses as much as digits as its factorization.

686000009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 686000009 is about 26191.6018792284. The cubic root of 686000009 is about 881.9447387833.

The spelling of 686000009 in words is "six hundred eighty-six million, nine", and thus it is an aban number.