681840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a tau number, because it is divible by the number of its divisors (60).
It is a congruent number.
2681840 is an apocalyptic number.
681840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 681840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1146132).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
681840 is a wasteful number, since it uses less digits than its factorization.
681840 is an evil number, because the sum of its binary digits is even.
The square root of 681840 is about 825.7360353043. The cubic root of 681840 is about 88.0158373700.
The spelling of 681840 in words is "six hundred eighty-one thousand, eight hundred forty".