7321 has 2 divisors, whose sum is σ = 7322. Its totient is φ = 7320.

The previous prime is 7309. The next prime is 7331. The reversal of 7321 is 1237.

7321 = 60² + 61².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3721 + 3600 = 61^2 + 60^2 .

It is an emirp because it is prime and its reverse (1237) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7321 - 2⁷ = 7193 is a prime.

It is a Chen prime.

7321 is a lucky number.

It is a plaindrome in base 11.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3660 + 3661.

It is an arithmetic number, because the mean of its divisors is an integer number (3661).

2⁷³²¹ is an apocalyptic number.

7321 is the 61-st centered square number.

It is an amenable number.

7321 is a deficient number, since it is larger than the sum of its proper divisors (1).

7321 is an equidigital number, since it uses as much as digits as its factorization.

7321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42, while the sum is 13.

The square root of 7321 is about 85.5628424025. The cubic root of 7321 is about 19.4173579014.

Adding to 7321 its reverse (1237), we get a palindrome (8558).

Subtracting from 7321 its reverse (1237), we obtain a square (6084 = 78²).

The spelling of 7321 in words is "seven thousand, three hundred twenty-one", and thus it is an iban number.