686668068 has 18 divisors (see below), whose sum is σ = 1735744374. Its totient is φ = 228889344.

The previous prime is 686668049. The next prime is 686668069. The reversal of 686668068 is 860866686.

686668068 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 601622784 + 85045284 = 24528^2 + 9222^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×686668068² = 943026071221705248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (686668069) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9537021 + ... + 9537092.

It is an arithmetic number, because the mean of its divisors is an integer number (96430243).

Almost surely, 2^686668068 is an apocalyptic number.

It is an amenable number.

686668068 is an abundant number, since it is smaller than the sum of its proper divisors (1049076306).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686668068 is a wasteful number, since it uses less digits than its factorization.

686668068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19074123 (or 19074118 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 54.

The square root of 686668068 is about 26204.3520812860. The cubic root of 686668068 is about 882.2309389559.

The spelling of 686668068 in words is "six hundred eighty-six million, six hundred sixty-eight thousand, sixty-eight".