9728905 has 4 divisors (see below), whose sum is σ = 11674692. Its totient is φ = 7783120.

The previous prime is 9728903. The next prime is 9728909. The reversal of 9728905 is 5098279.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6780816 + 2948089 = 2604^2 + 1717^2 .

It is not a de Polignac number, because 9728905 - 2¹ = 9728903 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

9728905 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (9728903) 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, 972886 + ... + 972895.

It is an arithmetic number, because the mean of its divisors is an integer number (2918673).

Almost surely, 2^9728905 is an apocalyptic number.

It is an amenable number.

9728905 is a deficient number, since it is larger than the sum of its proper divisors (1945787).

9728905 is a wasteful number, since it uses less digits than its factorization.

9728905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945786.

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

The square root of 9728905 is about 3119.1192667162. The cubic root of 9728905 is about 213.4787514937.

The spelling of 9728905 in words is "nine million, seven hundred twenty-eight thousand, nine hundred five".