685858 has 4 divisors (see below), whose sum is σ = 1028790. Its totient is φ = 342928.

The previous prime is 685849. The next prime is 685859. The reversal of 685858 is 858586.

685858 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.

It can be written as a sum of positive squares in only one way, i.e., 458329 + 227529 = 677^2 + 477^2 .

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 685858.

It is not an unprimeable number, because it can be changed into a prime (685859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171463 + ... + 171466.

2⁶⁸⁵⁸⁵⁸ is an apocalyptic number.

685858 is a deficient number, since it is larger than the sum of its proper divisors (342932).

685858 is a wasteful number, since it uses less digits than its factorization.

685858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342931.

The product of its digits is 76800, while the sum is 40.

The square root of 685858 is about 828.1654424087. The cubic root of 685858 is about 88.1883877397.

The spelling of 685858 in words is "six hundred eighty-five thousand, eight hundred fifty-eight".