685911 has 4 divisors (see below), whose sum is σ = 914552. Its totient is φ = 457272.

The previous prime is 685907. The next prime is 685939. The reversal of 685911 is 119586.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 685911 - 2² = 685907 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685991) 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 3 ways as a sum of consecutive naturals, for example, 114316 + ... + 114321.

It is an arithmetic number, because the mean of its divisors is an integer number (228638).

2⁶⁸⁵⁹¹¹ is an apocalyptic number.

685911 is a deficient number, since it is larger than the sum of its proper divisors (228641).

685911 is a wasteful number, since it uses less digits than its factorization.

685911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228640.

The product of its digits is 2160, while the sum is 30.

The square root of 685911 is about 828.1974402279. The cubic root of 685911 is about 88.1906592810.

It can be divided in two parts, 685 and 911, that added together give a triangular number (1596 = T₅₆).

The spelling of 685911 in words is "six hundred eighty-five thousand, nine hundred eleven".