681343728 has 80 divisors (see below), whose sum is σ = 1899211776. Its totient is φ = 209237760.

The previous prime is 681343727. The next prime is 681343739. The reversal of 681343728 is 827343186.

681343728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 681343728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681343727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 552873 + ... + 554103.

Almost surely, 2^681343728 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 681343728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (949605888).

681343728 is an abundant number, since it is smaller than the sum of its proper divisors (1217868048).

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

681343728 is a wasteful number, since it uses less digits than its factorization.

681343728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2142 (or 2136 counting only the distinct ones).

The product of its digits is 193536, while the sum is 42.

The square root of 681343728 is about 26102.5617133645. The cubic root of 681343728 is about 879.9447830368.

The spelling of 681343728 in words is "six hundred eighty-one million, three hundred forty-three thousand, seven hundred twenty-eight".