686685089 has 2 divisors, whose sum is σ = 686685090. Its totient is φ = 686685088.

The previous prime is 686685059. The next prime is 686685157. The reversal of 686685089 is 980586686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 686020864 + 664225 = 26192^2 + 815^2 .

It is a cyclic number.

It is not a de Polignac number, because 686685089 - 2¹² = 686680993 is a prime.

It is a super-2 number, since 2×686685089² = 943072822909875842, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (686685059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343342544 + 343342545.

It is an arithmetic number, because the mean of its divisors is an integer number (343342545).

Almost surely, 2^686685089 is an apocalyptic number.

It is an amenable number.

686685089 is a deficient number, since it is larger than the sum of its proper divisors (1).

686685089 is an equidigital number, since it uses as much as digits as its factorization.

686685089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4976640, while the sum is 56.

The square root of 686685089 is about 26204.6768535695. The cubic root of 686685089 is about 882.2382284210.

The spelling of 686685089 in words is "six hundred eighty-six million, six hundred eighty-five thousand, eighty-nine".