681444 has 36 divisors (see below), whose sum is σ = 1799616. Its totient is φ = 217008.

The previous prime is 681427. The next prime is 681449. The reversal of 681444 is 444186.

681444 = 161² + 162² + ... + 183².

681444 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 (36).

It is not an unprimeable number, because it can be changed into a prime (681449) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 417 + ... + 1239.

2⁶⁸¹⁴⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899808).

681444 is an abundant number, since it is smaller than the sum of its proper divisors (1118172).

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

681444 is a wasteful number, since it uses less digits than its factorization.

681444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856 (or 851 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 681444 is about 825.4962144068. The cubic root of 681444 is about 87.9987947493.

The spelling of 681444 in words is "six hundred eighty-one thousand, four hundred forty-four".