686635168 has 48 divisors (see below), whose sum is σ = 1445618664. Its totient is φ = 319897600.

The previous prime is 686635163. The next prime is 686635171. The reversal of 686635168 is 861536686.

It can be written as a sum of positive squares in 4 ways, for example, as 683717904 + 2917264 = 26148^2 + 1708^2 .

It is not an unprimeable number, because it can be changed into a prime (686635163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48696 + ... + 61192.

Almost surely, 2^686635168 is an apocalyptic number.

686635168 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686635168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (722809332).

686635168 is an abundant number, since it is smaller than the sum of its proper divisors (758983496).

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

686635168 is a wasteful number, since it uses less digits than its factorization.

686635168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12625 (or 12617 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 49.

The square root of 686635168 is about 26203.7243154480. The cubic root of 686635168 is about 882.2168487607.

The spelling of 686635168 in words is "six hundred eighty-six million, six hundred thirty-five thousand, one hundred sixty-eight".