8447221 has 8 divisors (see below), whose sum is σ = 8923904. Its totient is φ = 7983360.

The previous prime is 8447213. The next prime is 8447227. The reversal of 8447221 is 1227448.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8447221 - 2³ = 8447213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8447221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8447227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1836 + ... + 4501.

It is an arithmetic number, because the mean of its divisors is an integer number (1115488).

Almost surely, 2^8447221 is an apocalyptic number.

It is an amenable number.

8447221 is a deficient number, since it is larger than the sum of its proper divisors (476683).

8447221 is a wasteful number, since it uses less digits than its factorization.

8447221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6411.

The product of its digits is 3584, while the sum is 28.

The square root of 8447221 is about 2906.4103289109. The cubic root of 8447221 is about 203.6594745084.

It can be divided in two parts, 8447 and 221, that added together give a palindrome (8668).

The spelling of 8447221 in words is "eight million, four hundred forty-seven thousand, two hundred twenty-one".