9221521 has 4 divisors (see below), whose sum is σ = 9228852. Its totient is φ = 9214192.

The previous prime is 9221519. The next prime is 9221567. The reversal of 9221521 is 1251229.

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 5569600 + 3651921 = 2360^2 + 1911^2 .

It is a cyclic number.

It is not a de Polignac number, because 9221521 - 2¹ = 9221519 is a prime.

It is an Ulam number.

It is a Duffinian number.

9221521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 9221492 and 9221501.

It is not an unprimeable number, because it can be changed into a prime (9221501) 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 3 ways as a sum of consecutive naturals, for example, 1246 + ... + 4471.

It is an arithmetic number, because the mean of its divisors is an integer number (2307213).

Almost surely, 2^9221521 is an apocalyptic number.

It is an amenable number.

9221521 is a deficient number, since it is larger than the sum of its proper divisors (7331).

9221521 is a wasteful number, since it uses less digits than its factorization.

9221521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7330.

The product of its digits is 360, while the sum is 22.

The square root of 9221521 is about 3036.6957371459. The cubic root of 9221521 is about 209.7011698263.

The spelling of 9221521 in words is "nine million, two hundred twenty-one thousand, five hundred twenty-one".