685597 has 4 divisors (see below), whose sum is σ = 747936. Its totient is φ = 623260.

The previous prime is 685591. The next prime is 685609. The reversal of 685597 is 795586.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 685597 - 2¹⁹ = 161309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31153 + ... + 31174.

It is an arithmetic number, because the mean of its divisors is an integer number (186984).

2⁶⁸⁵⁵⁹⁷ is an apocalyptic number.

It is an amenable number.

685597 is a deficient number, since it is larger than the sum of its proper divisors (62339).

685597 is a wasteful number, since it uses less digits than its factorization.

685597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62338.

The product of its digits is 75600, while the sum is 40.

The square root of 685597 is about 828.0078502043. The cubic root of 685597 is about 88.1771997633.

It can be divided in two parts, 68 and 5597, that added together give a palindrome (5665).

The spelling of 685597 in words is "six hundred eighty-five thousand, five hundred ninety-seven".