685606 has 4 divisors (see below), whose sum is σ = 1028412. Its totient is φ = 342802.

The previous prime is 685591. The next prime is 685609. The reversal of 685606 is 606586.

685606 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 606586 = 2 ⋅303293.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685609) by changing a digit.

685606 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 as a sum of consecutive naturals, namely, 171400 + ... + 171403.

It is an arithmetic number, because the mean of its divisors is an integer number (257103).

2⁶⁸⁵⁶⁰⁶ is an apocalyptic number.

685606 is a deficient number, since it is larger than the sum of its proper divisors (342806).

685606 is a wasteful number, since it uses less digits than its factorization.

685606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342805.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 685606 is about 828.0132849176. The cubic root of 685606 is about 88.1775856028.

The spelling of 685606 in words is "six hundred eighty-five thousand, six hundred six".