685999866 has 16 divisors (see below), whose sum is σ = 1374128064. Its totient is φ = 228311904.

The previous prime is 685999859. The next prime is 685999877. The reversal of 685999866 is 668999586.

It is a junction number, because it is equal to n+sod(n) for n = 685999797 and 685999806.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84475 + ... + 92238.

It is an arithmetic number, because the mean of its divisors is an integer number (85883004).

Almost surely, 2^685999866 is an apocalyptic number.

685999866 is an abundant number, since it is smaller than the sum of its proper divisors (688128198).

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

685999866 is a wasteful number, since it uses less digits than its factorization.

685999866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177365.

The product of its digits is 50388480, while the sum is 66.

The square root of 685999866 is about 26191.5991493456. The cubic root of 685999866 is about 881.9446775014.

The spelling of 685999866 in words is "six hundred eighty-five million, nine hundred ninety-nine thousand, eight hundred sixty-six".