684685 has 8 divisors (see below), whose sum is σ = 844056. Its totient is φ = 532800.

The previous prime is 684683. The next prime is 684713. The reversal of 684685 is 586486.

684685 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 157609 + 527076 = 397^2 + 726^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 684685 - 2¹ = 684683 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a nialpdrome in base 7.

It is a zygodrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1666 + ... + 2035.

It is an arithmetic number, because the mean of its divisors is an integer number (105507).

2⁶⁸⁴⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

684685 is a deficient number, since it is larger than the sum of its proper divisors (159371).

684685 is a wasteful number, since it uses less digits than its factorization.

684685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3743.

The product of its digits is 46080, while the sum is 37.

The square root of 684685 is about 827.4569475205. The cubic root of 684685 is about 88.1380838344.

It can be divided in two parts, 684 and 685, that added together give a square (1369 = 37²).

The spelling of 684685 in words is "six hundred eighty-four thousand, six hundred eighty-five".