22533521 has 4 divisors (see below), whose sum is σ = 22549044. Its totient is φ = 22518000.

The previous prime is 22533509. The next prime is 22533527. The reversal of 22533521 is 12533522.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17850625 + 4682896 = 4225^2 + 2164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22533521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22533527) 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, 5330 + ... + 8571.

It is an arithmetic number, because the mean of its divisors is an integer number (5637261).

Almost surely, 2^22533521 is an apocalyptic number.

It is an amenable number.

22533521 is a deficient number, since it is larger than the sum of its proper divisors (15523).

22533521 is a wasteful number, since it uses less digits than its factorization.

22533521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15522.

The product of its digits is 1800, while the sum is 23.

The square root of 22533521 is about 4746.9485988369. The cubic root of 22533521 is about 282.4509367375.

Subtracting from 22533521 its reverse (12533522), we obtain a palindrome (9999999).

The spelling of 22533521 in words is "twenty-two million, five hundred thirty-three thousand, five hundred twenty-one".