8004221 has 2 divisors, whose sum is σ = 8004222. Its totient is φ = 8004220.

The previous prime is 8004211. The next prime is 8004223. The reversal of 8004221 is 1224008.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4044121 + 3960100 = 2011^2 + 1990^2 .

It is a cyclic number.

It is not a de Polignac number, because 8004221 - 2¹⁰ = 8003197 is a prime.

Together with 8004223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8004221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8004223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4002110 + 4002111.

It is an arithmetic number, because the mean of its divisors is an integer number (4002111).

Almost surely, 2^8004221 is an apocalyptic number.

It is an amenable number.

8004221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8004221 is an equidigital number, since it uses as much as digits as its factorization.

8004221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 8004221 is about 2829.1732007779. The cubic root of 8004221 is about 200.0351688154.

Adding to 8004221 its reverse (1224008), we get a palindrome (9228229).

The spelling of 8004221 in words is "eight million, four thousand, two hundred twenty-one".