8204221 has 2 divisors, whose sum is σ = 8204222. Its totient is φ = 8204220.

The previous prime is 8204191. The next prime is 8204233. The reversal of 8204221 is 1224028.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7901721 + 302500 = 2811^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 8204221 - 2⁷ = 8204093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8204281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4102110 + 4102111.

It is an arithmetic number, because the mean of its divisors is an integer number (4102111).

Almost surely, 2^8204221 is an apocalyptic number.

It is an amenable number.

8204221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8204221 is an equidigital number, since it uses as much as digits as its factorization.

8204221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 8204221 is about 2864.3011364031. The cubic root of 8204221 is about 201.6875622847.

Adding to 8204221 its reverse (1224028), we get a palindrome (9428249).

It can be divided in two parts, 820 and 4221, that added together give a square (5041 = 71²).

The spelling of 8204221 in words is "eight million, two hundred four thousand, two hundred twenty-one".