681864 has 16 divisors (see below), whose sum is σ = 1704720. Its totient is φ = 227280.

The previous prime is 681841. The next prime is 681883. The reversal of 681864 is 468186.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14182 + ... + 14229.

It is an arithmetic number, because the mean of its divisors is an integer number (106545).

2⁶⁸¹⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

681864 is an abundant number, since it is smaller than the sum of its proper divisors (1022856).

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

681864 is a wasteful number, since it uses less digits than its factorization.

681864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28420 (or 28416 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 681864 is about 825.7505676656. The cubic root of 681864 is about 88.0168700440.

The spelling of 681864 in words is "six hundred eighty-one thousand, eight hundred sixty-four".