8553221 has 2 divisors, whose sum is σ = 8553222. Its totient is φ = 8553220.

The previous prime is 8553199. The next prime is 8553229. The reversal of 8553221 is 1223558.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7230721 + 1322500 = 2689^2 + 1150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8553221 is a prime.

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 (8553229) 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, 4276610 + 4276611.

It is an arithmetic number, because the mean of its divisors is an integer number (4276611).

Almost surely, 2^8553221 is an apocalyptic number.

It is an amenable number.

8553221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8553221 is an equidigital number, since it uses as much as digits as its factorization.

8553221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 26.

The square root of 8553221 is about 2924.5890309580. The cubic root of 8553221 is about 204.5078099133.

Adding to 8553221 its reverse (1223558), we get a palindrome (9776779).

The spelling of 8553221 in words is "eight million, five hundred fifty-three thousand, two hundred twenty-one".