2213521 has 4 divisors (see below), whose sum is σ = 2216500. Its totient is φ = 2210544.

The previous prime is 2213489. The next prime is 2213531. The reversal of 2213521 is 1253122.

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 404496 + 1809025 = 636^2 + 1345^2 .

It is a cyclic number.

It is not a de Polignac number, because 2213521 - 2⁵ = 2213489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2213495 and 2213504.

It is not an unprimeable number, because it can be changed into a prime (2213531) 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, 655 + ... + 2203.

It is an arithmetic number, because the mean of its divisors is an integer number (554125).

2^2213521 is an apocalyptic number.

It is an amenable number.

2213521 is a deficient number, since it is larger than the sum of its proper divisors (2979).

2213521 is a wasteful number, since it uses less digits than its factorization.

2213521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2978.

The product of its digits is 120, while the sum is 16.

The square root of 2213521 is about 1487.7906438743. The cubic root of 2213521 is about 130.3250445878.

Adding to 2213521 its reverse (1253122), we get a palindrome (3466643).

The spelling of 2213521 in words is "two million, two hundred thirteen thousand, five hundred twenty-one".