9728509 has 16 divisors (see below), whose sum is σ = 11491200. Its totient is φ = 8232000.

The previous prime is 9728503. The next prime is 9728519. The reversal of 9728509 is 9058279.

It is not a de Polignac number, because 9728509 - 2⁹ = 9727997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9728503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38634 + ... + 38884.

It is an arithmetic number, because the mean of its divisors is an integer number (718200).

Almost surely, 2^9728509 is an apocalyptic number.

It is an amenable number.

9728509 is a deficient number, since it is larger than the sum of its proper divisors (1762691).

9728509 is a wasteful number, since it uses less digits than its factorization.

9728509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 9728509 is about 3119.0557866124. The cubic root of 9728509 is about 213.4758550138.

The spelling of 9728509 in words is "nine million, seven hundred twenty-eight thousand, five hundred nine".