8221891 has 2 divisors, whose sum is σ = 8221892. Its totient is φ = 8221890.

The previous prime is 8221859. The next prime is 8221903. The reversal of 8221891 is 1981228.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8221891 - 2⁵ = 8221859 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8221831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4110945 + 4110946.

It is an arithmetic number, because the mean of its divisors is an integer number (4110946).

Almost surely, 2^8221891 is an apocalyptic number.

8221891 is a deficient number, since it is larger than the sum of its proper divisors (1).

8221891 is an equidigital number, since it uses as much as digits as its factorization.

8221891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 31.

The square root of 8221891 is about 2867.3839993974. The cubic root of 8221891 is about 201.8322546219.

The spelling of 8221891 in words is "eight million, two hundred twenty-one thousand, eight hundred ninety-one".