9728009 has 2 divisors, whose sum is σ = 9728010. Its totient is φ = 9728008.

The previous prime is 9727999. The next prime is 9728023. The reversal of 9728009 is 9008279.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7038409 + 2689600 = 2653^2 + 1640^2 .

It is a cyclic number.

It is not a de Polignac number, because 9728009 - 2¹² = 9723913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9728009.

It is not a weakly prime, because it can be changed into another prime (9728039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4864004 + 4864005.

It is an arithmetic number, because the mean of its divisors is an integer number (4864005).

Almost surely, 2^9728009 is an apocalyptic number.

It is an amenable number.

9728009 is a deficient number, since it is larger than the sum of its proper divisors (1).

9728009 is an equidigital number, since it uses as much as digits as its factorization.

9728009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 9728009 is about 3118.9756331206. The cubic root of 9728009 is about 213.4721977300.

The spelling of 9728009 in words is "nine million, seven hundred twenty-eight thousand, nine".