22128821 has 8 divisors (see below), whose sum is σ = 25997664. Its totient is φ = 18569520.

The previous prime is 22128811. The next prime is 22128839. The reversal of 22128821 is 12882122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22128821 - 2¹⁰ = 22127797 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22128811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77231 + ... + 77516.

It is an arithmetic number, because the mean of its divisors is an integer number (3249708).

Almost surely, 2^22128821 is an apocalyptic number.

It is an amenable number.

22128821 is a deficient number, since it is larger than the sum of its proper divisors (3868843).

22128821 is a wasteful number, since it uses less digits than its factorization.

22128821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154771.

The product of its digits is 1024, while the sum is 26.

The square root of 22128821 is about 4704.1280807393. The cubic root of 22128821 is about 280.7497804214.

The spelling of 22128821 in words is "twenty-two million, one hundred twenty-eight thousand, eight hundred twenty-one".