8440321 has 2 divisors, whose sum is σ = 8440322. Its totient is φ = 8440320.

The previous prime is 8440319. The next prime is 8440331. The reversal of 8440321 is 1230448.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8439025 + 1296 = 2905^2 + 36^2 .

It is a cyclic number.

It is not a de Polignac number, because 8440321 - 2¹ = 8440319 is a prime.

Together with 8440319, it forms a pair of twin primes.

It is a Chen prime.

8440321 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 8440292 and 8440301.

It is not a weakly prime, because it can be changed into another prime (8440331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4220160 + 4220161.

It is an arithmetic number, because the mean of its divisors is an integer number (4220161).

Almost surely, 2^8440321 is an apocalyptic number.

It is an amenable number.

8440321 is a deficient number, since it is larger than the sum of its proper divisors (1).

8440321 is an equidigital number, since it uses as much as digits as its factorization.

8440321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 8440321 is about 2905.2230551199. The cubic root of 8440321 is about 203.6040072264.

Adding to 8440321 its reverse (1230448), we get a palindrome (9670769).

The spelling of 8440321 in words is "eight million, four hundred forty thousand, three hundred twenty-one".