685897 has 4 divisors (see below), whose sum is σ = 687616. Its totient is φ = 684180.

The previous prime is 685859. The next prime is 685907. The reversal of 685897 is 798586.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685297) 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, 88 + ... + 1174.

It is an arithmetic number, because the mean of its divisors is an integer number (171904).

2⁶⁸⁵⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

685897 is a deficient number, since it is larger than the sum of its proper divisors (1719).

685897 is a wasteful number, since it uses less digits than its factorization.

685897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1718.

The product of its digits is 120960, while the sum is 43.

The square root of 685897 is about 828.1889880939. The cubic root of 685897 is about 88.1900592626.

The spelling of 685897 in words is "six hundred eighty-five thousand, eight hundred ninety-seven".