22521216 has 64 divisors (see below), whose sum is σ = 60318720. Its totient is φ = 7444992.

The previous prime is 22521211. The next prime is 22521217. The reversal of 22521216 is 61212522.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 22521192 and 22521201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22521211) 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, 85501 + ... + 85763.

It is an arithmetic number, because the mean of its divisors is an integer number (942480).

Almost surely, 2^22521216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22521216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30159360).

22521216 is an abundant number, since it is smaller than the sum of its proper divisors (37797504).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

22521216 is a wasteful number, since it uses less digits than its factorization.

22521216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503 (or 491 counting only the distinct ones).

The product of its digits is 480, while the sum is 21.

The square root of 22521216 is about 4745.6523260770. The cubic root of 22521216 is about 282.3995142130.

Adding to 22521216 its reverse (61212522), we get a palindrome (83733738).

The spelling of 22521216 in words is "twenty-two million, five hundred twenty-one thousand, two hundred sixteen".