685841 has 4 divisors (see below), whose sum is σ = 738612. Its totient is φ = 633072.

The previous prime is 685819. The next prime is 685849. The reversal of 685841 is 148586.

685841 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, and also an emirpimes, since its reverse is a distinct semiprime: 148586 = 2 ⋅74293.

It can be written as a sum of positive squares in 2 ways, for example, as 355216 + 330625 = 596^2 + 575^2 .

It is a cyclic number.

It is not a de Polignac number, because 685841 - 2¹⁸ = 423697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 685798 and 685807.

It is not an unprimeable number, because it can be changed into a prime (685849) 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, 26366 + ... + 26391.

It is an arithmetic number, because the mean of its divisors is an integer number (184653).

2⁶⁸⁵⁸⁴¹ is an apocalyptic number.

It is an amenable number.

685841 is a deficient number, since it is larger than the sum of its proper divisors (52771).

685841 is a wasteful number, since it uses less digits than its factorization.

685841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52770.

The product of its digits is 7680, while the sum is 32.

The square root of 685841 is about 828.1551786954. The cubic root of 685841 is about 88.1876591074.

The spelling of 685841 in words is "six hundred eighty-five thousand, eight hundred forty-one".