729756721 has 2 divisors, whose sum is σ = 729756722. Its totient is φ = 729756720.

The previous prime is 729756707. The next prime is 729756737. The reversal of 729756721 is 127657927.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 518199696 + 211557025 = 22764^2 + 14545^2 .

It is a cyclic number.

It is not a de Polignac number, because 729756721 - 2⁵ = 729756689 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (729756761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364878360 + 364878361.

It is an arithmetic number, because the mean of its divisors is an integer number (364878361).

Almost surely, 2^729756721 is an apocalyptic number.

It is an amenable number.

729756721 is a deficient number, since it is larger than the sum of its proper divisors (1).

729756721 is an equidigital number, since it uses as much as digits as its factorization.

729756721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 370440, while the sum is 46.

The square root of 729756721 is about 27014.0097171819. The cubic root of 729756721 is about 900.3113001312.

The spelling of 729756721 in words is "seven hundred twenty-nine million, seven hundred fifty-six thousand, seven hundred twenty-one".