685899 has 12 divisors (see below), whose sum is σ = 1049256. Its totient is φ = 430272.

The previous prime is 685859. The next prime is 685907. The reversal of 685899 is 998586.

685899 is a `hidden beast` number, since 68 + 589 + 9 = 666.

It is not a de Polignac number, because 685899 - 2¹⁶ = 620363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (685819) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2089 + ... + 2394.

It is an arithmetic number, because the mean of its divisors is an integer number (87438).

2⁶⁸⁵⁸⁹⁹ is an apocalyptic number.

685899 is a deficient number, since it is larger than the sum of its proper divisors (363357).

685899 is a wasteful number, since it uses less digits than its factorization.

685899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4506 (or 4503 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 685899 is about 828.1901955469. The cubic root of 685899 is about 88.1901449800.

It can be divided in two parts, 6 and 85899, that added together give a triangular number (85905 = T₄₁₄).

The spelling of 685899 in words is "six hundred eighty-five thousand, eight hundred ninety-nine".