9218221 has 8 divisors (see below), whose sum is σ = 9406584. Its totient is φ = 9031680.

The previous prime is 9218213. The next prime is 9218257. The reversal of 9218221 is 1228129.

It can be written as a sum of positive squares in 4 ways, for example, as 6375625 + 2842596 = 2525^2 + 1686^2 .

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 9218221 - 2³ = 9218213 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 (9218281) 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, 14061 + ... + 14701.

It is an arithmetic number, because the mean of its divisors is an integer number (1175823).

Almost surely, 2^9218221 is an apocalyptic number.

It is an amenable number.

9218221 is a deficient number, since it is larger than the sum of its proper divisors (188363).

9218221 is a wasteful number, since it uses less digits than its factorization.

9218221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911.

The product of its digits is 576, while the sum is 25.

The square root of 9218221 is about 3036.1523347816. The cubic root of 9218221 is about 209.6761523906.

The spelling of 9218221 in words is "nine million, two hundred eighteen thousand, two hundred twenty-one".