8309221 has 4 divisors (see below), whose sum is σ = 8315244. Its totient is φ = 8303200.

The previous prime is 8309173. The next prime is 8309227. The reversal of 8309221 is 1229038.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6832996 + 1476225 = 2614^2 + 1215^2 .

It is a cyclic number.

It is not a de Polignac number, because 8309221 - 2⁹ = 8308709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8309227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201 + ... + 4081.

It is an arithmetic number, because the mean of its divisors is an integer number (2078811).

Almost surely, 2^8309221 is an apocalyptic number.

It is an amenable number.

8309221 is a deficient number, since it is larger than the sum of its proper divisors (6023).

8309221 is a wasteful number, since it uses less digits than its factorization.

8309221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6022.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 8309221 is about 2882.5719418603. The cubic root of 8309221 is about 202.5443361744.

The spelling of 8309221 in words is "eight million, three hundred nine thousand, two hundred twenty-one".