9217728 has 84 divisors (see below), whose sum is σ = 28476448. Its totient is φ = 2833920.

The previous prime is 9217727. The next prime is 9217739. The reversal of 9217728 is 8277129.

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 = 9217692 and 9217701.

It is not an unprimeable number, because it can be changed into a prime (9217721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6873 + ... + 8103.

Almost surely, 2^9217728 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 9217728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14238224).

9217728 is an abundant number, since it is smaller than the sum of its proper divisors (19258720).

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

9217728 is a wasteful number, since it uses less digits than its factorization.

9217728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262 (or 1249 counting only the distinct ones).

The product of its digits is 14112, while the sum is 36.

The square root of 9217728 is about 3036.0711454115. The cubic root of 9217728 is about 209.6724144248.

It can be divided in two parts, 921 and 7728, that added together give a square (8649 = 93²).

The spelling of 9217728 in words is "nine million, two hundred seventeen thousand, seven hundred twenty-eight".