9728 has 20 divisors (see below), whose sum is σ = 20460. Its totient is φ = 4608.

The previous prime is 9721. The next prime is 9733. The reversal of 9728 is 8279.

Its product of digits (1008) is a multiple of the sum of its prime divisors (21).

It is a plaindrome in base 14.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 9697 and 9706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9721) by changing a digit.

9728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 503 + ... + 521.

It is an arithmetic number, because the mean of its divisors is an integer number (1023).

2⁹⁷²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10230).

9728 is an abundant number, since it is smaller than the sum of its proper divisors (10732).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9728 is an equidigital number, since it uses as much as digits as its factorization.

9728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37 (or 21 counting only the distinct ones).

The product of its digits is 1008, while the sum is 26.

The square root of 9728 is about 98.6306240475. The cubic root of 9728 is about 21.3472131898.

It can be divided in two parts, 972 and 8, that multiplied together give a 5-th power (7776 = 6⁵).

The spelling of 9728 in words is "nine thousand, seven hundred twenty-eight".