685189 has 4 divisors (see below), whose sum is σ = 687424. Its totient is φ = 682956.

The previous prime is 685177. The next prime is 685199. The reversal of 685189 is 981586.

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 a cyclic number.

It is not a de Polignac number, because 685189 - 2¹⁷ = 554117 is a prime.

It is a Duffinian number.

685189 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685109) 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, 567 + ... + 1300.

It is an arithmetic number, because the mean of its divisors is an integer number (171856).

2⁶⁸⁵¹⁸⁹ is an apocalyptic number.

It is an amenable number.

685189 is a deficient number, since it is larger than the sum of its proper divisors (2235).

685189 is a wasteful number, since it uses less digits than its factorization.

685189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2234.

The product of its digits is 17280, while the sum is 37.

The square root of 685189 is about 827.7614390632. The cubic root of 685189 is about 88.1597048227.

The spelling of 685189 in words is "six hundred eighty-five thousand, one hundred eighty-nine".