8221121 has 4 divisors (see below), whose sum is σ = 8228292. Its totient is φ = 8213952.

The previous prime is 8221111. The next prime is 8221139. The reversal of 8221121 is 1211228.

It is a happy number.

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 2768896 + 5452225 = 1664^2 + 2335^2 .

It is a cyclic number.

It is not a de Polignac number, because 8221121 - 2¹⁰ = 8220097 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 8221121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8221111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1436 + ... + 4301.

It is an arithmetic number, because the mean of its divisors is an integer number (2057073).

Almost surely, 2^8221121 is an apocalyptic number.

It is an amenable number.

8221121 is a deficient number, since it is larger than the sum of its proper divisors (7171).

8221121 is a wasteful number, since it uses less digits than its factorization.

8221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7170.

The product of its digits is 64, while the sum is 17.

The square root of 8221121 is about 2867.2497275264. The cubic root of 8221121 is about 201.8259537321.

Adding to 8221121 its reverse (1211228), we get a palindrome (9432349).

The spelling of 8221121 in words is "eight million, two hundred twenty-one thousand, one hundred twenty-one".