681082721 has 8 divisors (see below), whose sum is σ = 782104800. Its totient is φ = 586578240.

The previous prime is 681082711. The next prime is 681082733. The reversal of 681082721 is 127280186.

681082721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681082721 - 2⁶ = 681082657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681082711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1629176 + ... + 1629593.

It is an arithmetic number, because the mean of its divisors is an integer number (97763100).

Almost surely, 2^681082721 is an apocalyptic number.

It is an amenable number.

681082721 is a deficient number, since it is larger than the sum of its proper divisors (101022079).

681082721 is a wasteful number, since it uses less digits than its factorization.

681082721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3258799.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 681082721 is about 26097.5615910759. The cubic root of 681082721 is about 879.8324065313.

The spelling of 681082721 in words is "six hundred eighty-one million, eighty-two thousand, seven hundred twenty-one".