684870 has 32 divisors (see below), whose sum is σ = 1690848. Its totient is φ = 177408.

The previous prime is 684869. The next prime is 684889. The reversal of 684870 is 78486.

684870 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 684870.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 802 + ... + 1418.

It is an arithmetic number, because the mean of its divisors is an integer number (52839).

2⁶⁸⁴⁸⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (845424).

684870 is an abundant number, since it is smaller than the sum of its proper divisors (1005978).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

684870 is a wasteful number, since it uses less digits than its factorization.

684870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 684870 is about 827.5687282637. The cubic root of 684870 is about 88.1460213420.

The spelling of 684870 in words is "six hundred eighty-four thousand, eight hundred seventy".