8442221 has 2 divisors, whose sum is σ = 8442222. Its totient is φ = 8442220.

The previous prime is 8442167. The next prime is 8442223. The reversal of 8442221 is 1222448.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7896100 + 546121 = 2810^2 + 739^2 .

It is a cyclic number.

It is not a de Polignac number, because 8442221 - 2⁶ = 8442157 is a prime.

Together with 8442223, it forms a pair of twin primes.

It is a Chen 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 (8442223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4221110 + 4221111.

It is an arithmetic number, because the mean of its divisors is an integer number (4221111).

Almost surely, 2^8442221 is an apocalyptic number.

It is an amenable number.

8442221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8442221 is an equidigital number, since it uses as much as digits as its factorization.

8442221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1024, while the sum is 23.

The square root of 8442221 is about 2905.5500339867. The cubic root of 8442221 is about 203.6192838409.

Adding to 8442221 its reverse (1222448), we get a palindrome (9664669).

The spelling of 8442221 in words is "eight million, four hundred forty-two thousand, two hundred twenty-one".