9897728 has 54 divisors (see below), whose sum is σ = 21130872. Its totient is φ = 4618240.

The previous prime is 9897703. The next prime is 9897743. The reversal of 9897728 is 8277989.

It is a happy number.

It is a d-powerful number, because it can be written as 9⁷ + 8⁴ + 9⁷ + 7 + 7 + 2¹⁶ + 8⁶ .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 241388 + ... + 241428.

Almost surely, 2^9897728 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 9897728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10565436).

9897728 is an abundant number, since it is smaller than the sum of its proper divisors (11233144).

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

9897728 is an equidigital number, since it uses as much as digits as its factorization.

9897728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 66 counting only the distinct ones).

The product of its digits is 508032, while the sum is 50.

The square root of 9897728 is about 3146.0654792931. The cubic root of 9897728 is about 214.7064897035.

The spelling of 9897728 in words is "nine million, eight hundred ninety-seven thousand, seven hundred twenty-eight".