9728640 has 128 divisors (see below), whose sum is σ = 34516800. Its totient is φ = 2589696.

The previous prime is 9728639. The next prime is 9728651. The reversal of 9728640 is 468279.

9728640 is a `hidden beast` number, since 9 + 7 + 2 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 9728595 and 9728604.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16999 + ... + 17561.

Almost surely, 2^9728640 is an apocalyptic number.

9728640 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17258400).

9728640 is an abundant number, since it is smaller than the sum of its proper divisors (24788160).

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

9728640 is a wasteful number, since it uses less digits than its factorization.

9728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 9728640 is about 3119.0767864867. The cubic root of 9728640 is about 213.4768132015.

The spelling of 9728640 in words is "nine million, seven hundred twenty-eight thousand, six hundred forty".