22212121 has 4 divisors (see below), whose sum is σ = 23381200. Its totient is φ = 21043044.

The previous prime is 22212109. The next prime is 22212131. The reversal of 22212121 is 12121222.

It is a happy number.

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 22212121 - 2⁷ = 22211993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22212101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 584511 + ... + 584548.

It is an arithmetic number, because the mean of its divisors is an integer number (5845300).

Almost surely, 2^22212121 is an apocalyptic number.

It is an amenable number.

22212121 is a deficient number, since it is larger than the sum of its proper divisors (1169079).

22212121 is a wasteful number, since it uses less digits than its factorization.

22212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1169078.

The product of its digits is 32, while the sum is 13.

The square root of 22212121 is about 4712.9736897207. The cubic root of 22212121 is about 281.1016168073.

Adding to 22212121 its reverse (12121222), we get a palindrome (34333343).

The spelling of 22212121 in words is "twenty-two million, two hundred twelve thousand, one hundred twenty-one".