686807856 has 160 divisors (see below), whose sum is σ = 2262712320. Its totient is φ = 195388416.

The previous prime is 686807843. The next prime is 686807861. The reversal of 686807856 is 658708686.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1157896 + ... + 1158488.

It is an arithmetic number, because the mean of its divisors is an integer number (14141952).

Almost surely, 2^686807856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686807856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1131356160).

686807856 is an abundant number, since it is smaller than the sum of its proper divisors (1575904464).

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

686807856 is a wasteful number, since it uses less digits than its factorization.

686807856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000 (or 988 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The square root of 686807856 is about 26207.0192124171. The cubic root of 686807856 is about 882.2908014216.

The spelling of 686807856 in words is "six hundred eighty-six million, eight hundred seven thousand, eight hundred fifty-six".