686506857 has 16 divisors (see below), whose sum is σ = 933464832. Its totient is φ = 448675920.

The previous prime is 686506823. The next prime is 686506867. The reversal of 686506857 is 758605686.

686506857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 686506857 - 2⁷ = 686506729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (686506867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34318 + ... + 50504.

It is an arithmetic number, because the mean of its divisors is an integer number (58341552).

Almost surely, 2^686506857 is an apocalyptic number.

686506857 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

It is an amenable number.

686506857 is a deficient number, since it is larger than the sum of its proper divisors (246957975).

686506857 is a wasteful number, since it uses less digits than its factorization.

686506857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16468.

The product of its (nonzero) digits is 2419200, while the sum is 51.

The square root of 686506857 is about 26201.2758658810. The cubic root of 686506857 is about 882.1618922699.

The spelling of 686506857 in words is "six hundred eighty-six million, five hundred six thousand, eight hundred fifty-seven".