222222121 has 4 divisors (see below), whose sum is σ = 242424144. Its totient is φ = 202020100.

The previous prime is 222222103. The next prime is 222222131. The reversal of 222222121 is 121222222.

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 222222121 - 2¹⁷ = 222091049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 222222095 and 222222104.

It is not an unprimeable number, because it can be changed into a prime (222222131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10100995 + ... + 10101016.

It is an arithmetic number, because the mean of its divisors is an integer number (60606036).

Almost surely, 2^222222121 is an apocalyptic number.

It is an amenable number.

222222121 is a deficient number, since it is larger than the sum of its proper divisors (20202023).

222222121 is a wasteful number, since it uses less digits than its factorization.

222222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20202022.

The product of its digits is 128, while the sum is 16.

The square root of 222222121 is about 14907.1164549017. The cubic root of 222222121 is about 605.7067723109.

Adding to 222222121 its reverse (121222222), we get a palindrome (343444343).

It can be divided in two parts, 222222 and 121, that multiplied together give a palindrome (26888862).

The spelling of 222222121 in words is "two hundred twenty-two million, two hundred twenty-two thousand, one hundred twenty-one".