728699542321 has 9 divisors (see below), whose sum is σ = 732660398379. Its totient is φ = 724759998336.

The previous prime is 728699542309. The next prime is 728699542327. The reversal of 728699542321 is 123245996827.

The square root of 728699542321 is 853639.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 176555434225 + 552144108096 = 420185^2 + 743064^2 .

It is not a de Polignac number, because 728699542321 - 2⁵ = 728699542289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728699542327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 164750116 + ... + 164754538.

It is an arithmetic number, because the mean of its divisors is an integer number (81406710931).

Almost surely, 2^728699542321 is an apocalyptic number.

728699542321 is the 853639-th square number.

728699542321 is the 426820-th centered octagonal number.

It is an amenable number.

728699542321 is a deficient number, since it is larger than the sum of its proper divisors (3960856058).

728699542321 is an frugal number, since it uses more digits than its factorization.

728699542321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9232 (or 4616 counting only the distinct ones).

The product of its digits is 13063680, while the sum is 58.

The spelling of 728699542321 in words is "seven hundred twenty-eight billion, six hundred ninety-nine million, five hundred forty-two thousand, three hundred twenty-one".