681940039 has 16 divisors (see below), whose sum is σ = 784224000. Its totient is φ = 586465920.

The previous prime is 681940033. The next prime is 681940117. The reversal of 681940039 is 930049186.

It is a cyclic number.

It is not a de Polignac number, because 681940039 - 2⁷ = 681939911 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681939983 and 681940010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681940033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 173407 + ... + 177295.

It is an arithmetic number, because the mean of its divisors is an integer number (49014000).

Almost surely, 2^681940039 is an apocalyptic number.

681940039 is a deficient number, since it is larger than the sum of its proper divisors (102283961).

681940039 is a wasteful number, since it uses less digits than its factorization.

681940039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4758.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 681940039 is about 26113.9816764889. The cubic root of 681940039 is about 880.2014169638.

The spelling of 681940039 in words is "six hundred eighty-one million, nine hundred forty thousand, thirty-nine".