686347889 has 2 divisors, whose sum is σ = 686347890. Its totient is φ = 686347888.

The previous prime is 686347861. The next prime is 686347973. The reversal of 686347889 is 988743686.

686347889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 666052864 + 20295025 = 25808^2 + 4505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686347889 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (686347589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343173944 + 343173945.

It is an arithmetic number, because the mean of its divisors is an integer number (343173945).

Almost surely, 2^686347889 is an apocalyptic number.

It is an amenable number.

686347889 is a deficient number, since it is larger than the sum of its proper divisors (1).

686347889 is an equidigital number, since it uses as much as digits as its factorization.

686347889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13934592, while the sum is 59.

The square root of 686347889 is about 26198.2420975149. The cubic root of 686347889 is about 882.0937956753.

The spelling of 686347889 in words is "six hundred eighty-six million, three hundred forty-seven thousand, eight hundred eighty-nine".