685693 has 4 divisors (see below), whose sum is σ = 692860. Its totient is φ = 678528.

The previous prime is 685679. The next prime is 685697. The reversal of 685693 is 396586.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 273529 + 412164 = 523^2 + 642^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685693 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 (685697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3438 + ... + 3631.

It is an arithmetic number, because the mean of its divisors is an integer number (173215).

2⁶⁸⁵⁶⁹³ is an apocalyptic number.

It is an amenable number.

685693 is a deficient number, since it is larger than the sum of its proper divisors (7167).

685693 is an equidigital number, since it uses as much as digits as its factorization.

685693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7166.

The product of its digits is 38880, while the sum is 37.

The square root of 685693 is about 828.0658186400. The cubic root of 685693 is about 88.1813152111.

It can be divided in two parts, 685 and 693, that added together give a triangular number (1378 = T₅₂).

The spelling of 685693 in words is "six hundred eighty-five thousand, six hundred ninety-three".