9728409 has 4 divisors (see below), whose sum is σ = 12971216. Its totient is φ = 6485604.

The previous prime is 9728401. The next prime is 9728417. The reversal of 9728409 is 9048279.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9048279 = 3 ⋅3016093.

It is an interprime number because it is at equal distance from previous prime (9728401) and next prime (9728417).

It is not a de Polignac number, because 9728409 - 2³ = 9728401 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9728401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1621399 + ... + 1621404.

It is an arithmetic number, because the mean of its divisors is an integer number (3242804).

Almost surely, 2^9728409 is an apocalyptic number.

It is an amenable number.

9728409 is a deficient number, since it is larger than the sum of its proper divisors (3242807).

9728409 is a wasteful number, since it uses less digits than its factorization.

9728409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3242806.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 9728409 is about 3119.0397560788. The cubic root of 9728409 is about 213.4751235671.

The spelling of 9728409 in words is "nine million, seven hundred twenty-eight thousand, four hundred nine".