723728209 has 4 divisors (see below), whose sum is σ = 723839140. Its totient is φ = 723617280.

The previous prime is 723728179. The next prime is 723728249. The reversal of 723728209 is 902827327.

723728209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 417303184 + 306425025 = 20428^2 + 17505^2 .

It is a cyclic number.

It is not a de Polignac number, because 723728209 - 2¹⁷ = 723597137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (723728249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45024 + ... + 58945.

It is an arithmetic number, because the mean of its divisors is an integer number (180959785).

Almost surely, 2^723728209 is an apocalyptic number.

It is an amenable number.

723728209 is a deficient number, since it is larger than the sum of its proper divisors (110931).

723728209 is a wasteful number, since it uses less digits than its factorization.

723728209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110930.

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 723728209 is about 26902.1971035825. The cubic root of 723728209 is about 897.8252880578.

The spelling of 723728209 in words is "seven hundred twenty-three million, seven hundred twenty-eight thousand, two hundred nine".