681346728 has 80 divisors (see below), whose sum is σ = 1916698080. Its totient is φ = 227063088.

The previous prime is 681346727. The next prime is 681346763. The reversal of 681346728 is 827643186.

It is not an unprimeable number, because it can be changed into a prime (681346727) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 155301 + ... + 159627.

It is an arithmetic number, because the mean of its divisors is an integer number (23958726).

Almost surely, 2^681346728 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 681346728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (958349040).

681346728 is an abundant number, since it is smaller than the sum of its proper divisors (1235351352).

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

681346728 is an frugal number, since it uses more digits than its factorization.

681346728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4360 (or 4332 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 681346728 is about 26102.6191789253. The cubic root of 681346728 is about 879.9460745193.

The spelling of 681346728 in words is "six hundred eighty-one million, three hundred forty-six thousand, seven hundred twenty-eight".