9217321 has 2 divisors, whose sum is σ = 9217322. Its totient is φ = 9217320.

The previous prime is 9217309. The next prime is 9217339. The reversal of 9217321 is 1237129.

9217321 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9217296 + 25 = 3036^2 + 5^2 .

It is an emirp because it is prime and its reverse (1237129) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9217321 - 2⁷ = 9217193 is a prime.

9217321 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (9217381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4608660 + 4608661.

It is an arithmetic number, because the mean of its divisors is an integer number (4608661).

Almost surely, 2^9217321 is an apocalyptic number.

It is an amenable number.

9217321 is a deficient number, since it is larger than the sum of its proper divisors (1).

9217321 is an equidigital number, since it uses as much as digits as its factorization.

9217321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 25.

The square root of 9217321 is about 3036.0041172568. The cubic root of 9217321 is about 209.6693284175.

Subtracting from 9217321 its sum of digits (25), we obtain a square (9217296 = 3036²).

The spelling of 9217321 in words is "nine million, two hundred seventeen thousand, three hundred twenty-one".