22221021 has 4 divisors (see below), whose sum is σ = 29628032. Its totient is φ = 14814012.

The previous prime is 22221007. The next prime is 22221029. The reversal of 22221021 is 12012222.

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 not a de Polignac number, because 22221021 - 2⁹ = 22220509 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 22220988 and 22221006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22221029) 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, 3703501 + ... + 3703506.

It is an arithmetic number, because the mean of its divisors is an integer number (7407008).

Almost surely, 2^22221021 is an apocalyptic number.

It is an amenable number.

22221021 is a deficient number, since it is larger than the sum of its proper divisors (7407011).

22221021 is an equidigital number, since it uses as much as digits as its factorization.

22221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7407010.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 22221021 is about 4713.9177973316. The cubic root of 22221021 is about 281.1391559257.

Adding to 22221021 its reverse (12012222), we get a palindrome (34233243).

The spelling of 22221021 in words is "twenty-two million, two hundred twenty-one thousand, twenty-one".