685686 has 8 divisors (see below), whose sum is σ = 1371384. Its totient is φ = 228560.

The previous prime is 685679. The next prime is 685697. The reversal of 685686 is 686586.

It is a sphenic number, since it is the product of 3 distinct primes.

685686 is an admirable number.

It is a congruent number.

It is an unprimeable number.

685686 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57135 + ... + 57146.

It is an arithmetic number, because the mean of its divisors is an integer number (171423).

2⁶⁸⁵⁶⁸⁶ is an apocalyptic number.

685686 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

685686 is a wasteful number, since it uses less digits than its factorization.

685686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114286.

The product of its digits is 69120, while the sum is 39.

The square root of 685686 is about 828.0615919121. The cubic root of 685686 is about 88.1810151394.

Subtracting 685686 from its reverse (686586), we obtain a square (900 = 30²).

The spelling of 685686 in words is "six hundred eighty-five thousand, six hundred eighty-six".