685806 has 16 divisors (see below), whose sum is σ = 1496448. Its totient is φ = 207800.

The previous prime is 685793. The next prime is 685819. The reversal of 685806 is 608586.

It is an interprime number because it is at equal distance from previous prime (685793) and next prime (685819).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 5130 + ... + 5261.

It is an arithmetic number, because the mean of its divisors is an integer number (93528).

2⁶⁸⁵⁸⁰⁶ is an apocalyptic number.

685806 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

685806 is an abundant number, since it is smaller than the sum of its proper divisors (810642).

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

685806 is a wasteful number, since it uses less digits than its factorization.

685806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10407.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 685806 is about 828.1340471204. The cubic root of 685806 is about 88.1861589441.

It can be divided in two parts, 68580 and 6, that added together give a palindrome (68586).

The spelling of 685806 in words is "six hundred eighty-five thousand, eight hundred six".