9997128 has 64 divisors (see below), whose sum is σ = 28684800. Its totient is φ = 3222720.

The previous prime is 9997123. The next prime is 9997129. The reversal of 9997128 is 8217999.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (9997123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5950 + ... + 7442.

It is an arithmetic number, because the mean of its divisors is an integer number (448200).

Almost surely, 2^9997128 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 9997128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14342400).

9997128 is an abundant number, since it is smaller than the sum of its proper divisors (18687672).

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

9997128 is a wasteful number, since it uses less digits than its factorization.

9997128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1539 (or 1529 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 9997128 is about 3161.8235244871. The cubic root of 9997128 is about 215.4228419069.

It can be divided in two parts, 99971 and 28, that added together give a palindrome (99999).

The spelling of 9997128 in words is "nine million, nine hundred ninety-seven thousand, one hundred twenty-eight".