22021021 has 4 divisors (see below), whose sum is σ = 24022944. Its totient is φ = 20019100.

The previous prime is 22021009. The next prime is 22021049. The reversal of 22021021 is 12012022.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 22021021 - 2¹¹ = 22018973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22020989 and 22021007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22021621) 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, 1000945 + ... + 1000966.

It is an arithmetic number, because the mean of its divisors is an integer number (6005736).

Almost surely, 2^22021021 is an apocalyptic number.

It is an amenable number.

22021021 is a deficient number, since it is larger than the sum of its proper divisors (2001923).

22021021 is a wasteful number, since it uses less digits than its factorization.

22021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001922.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 22021021 is about 4692.6560709261. The cubic root of 22021021 is about 280.2931496088.

Adding to 22021021 its reverse (12012022), we get a palindrome (34033043).

It can be divided in two parts, 2202 and 1021, that added together give a palindrome (3223).

The spelling of 22021021 in words is "twenty-two million, twenty-one thousand, twenty-one".