685603 has 4 divisors (see below), whose sum is σ = 687280. Its totient is φ = 683928.

The previous prime is 685591. The next prime is 685609. The reversal of 685603 is 306586.

685603 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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 685603 - 2¹⁷ = 554531 is a prime.

It is a Duffinian number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 226 + ... + 1192.

It is an arithmetic number, because the mean of its divisors is an integer number (171820).

2⁶⁸⁵⁶⁰³ is an apocalyptic number.

685603 is a deficient number, since it is larger than the sum of its proper divisors (1677).

685603 is an equidigital number, since it uses as much as digits as its factorization.

685603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1676.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 685603 is about 828.0114733505. The cubic root of 685603 is about 88.1774569900.

It can be divided in two parts, 68 and 5603, that added together give a triangular number (5671 = T₁₀₆).

The spelling of 685603 in words is "six hundred eighty-five thousand, six hundred three".