681040 has 20 divisors (see below), whose sum is σ = 1583604. Its totient is φ = 272384.

The previous prime is 681019. The next prime is 681041. The reversal of 681040 is 40186.

It can be written as a sum of positive squares in 2 ways, for example, as 501264 + 179776 = 708^2 + 424^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 680999 and 681017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4177 + ... + 4336.

2⁶⁸¹⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

681040 is an abundant number, since it is smaller than the sum of its proper divisors (902564).

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

681040 is a wasteful number, since it uses less digits than its factorization.

681040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8526 (or 8520 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 681040 is about 825.2514768239. The cubic root of 681040 is about 87.9814010280.

The spelling of 681040 in words is "six hundred eighty-one thousand, forty".