8142221 has 2 divisors, whose sum is σ = 8142222. Its totient is φ = 8142220.

The previous prime is 8142157. The next prime is 8142229. The reversal of 8142221 is 1222418.

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., 5692996 + 2449225 = 2386^2 + 1565^2 .

It is a cyclic number.

It is not a de Polignac number, because 8142221 - 2⁶ = 8142157 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 8142193 and 8142202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8142229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4071110 + 4071111.

It is an arithmetic number, because the mean of its divisors is an integer number (4071111).

Almost surely, 2^8142221 is an apocalyptic number.

It is an amenable number.

8142221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8142221 is an equidigital number, since it uses as much as digits as its factorization.

8142221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 256, while the sum is 20.

The square root of 8142221 is about 2853.4577270392. The cubic root of 8142221 is about 201.1782203539.

Adding to 8142221 its reverse (1222418), we get a palindrome (9364639).

The spelling of 8142221 in words is "eight million, one hundred forty-two thousand, two hundred twenty-one".