729000009 has 6 divisors (see below), whose sum is σ = 1053000026. Its totient is φ = 486000000.

The previous prime is 729000007. The next prime is 729000017. The reversal of 729000009 is 900000927.

729000009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 729000000 + 9 = 27000^2 + 3^2 .

It is not a de Polignac number, because 729000009 - 2¹ = 729000007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (729000007) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40499992 + ... + 40500009.

Almost surely, 2^729000009 is an apocalyptic number.

It is an amenable number.

729000009 is a deficient number, since it is larger than the sum of its proper divisors (324000017).

729000009 is a wasteful number, since it uses less digits than its factorization.

729000009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81000007 (or 81000004 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 27.

The square root of 729000009 is about 27000.0001666667. Note that the first 3 decimals coincide. The cubic root of 729000009 is about 900.0000037037. Note that the first 5 decimals are identical.

The spelling of 729000009 in words is "seven hundred twenty-nine million, nine", and thus it is an aban number.