211222121 has 4 divisors (see below), whose sum is σ = 230424144. Its totient is φ = 192020100.

The previous prime is 211222111. The next prime is 211222147. The reversal of 211222121 is 121222112.

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 211222121 - 2⁶ = 211222057 is a prime.

It is a super-2 number, since 2×211222121² = 89229568799477282, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211222096 and 211222105.

It is not an unprimeable number, because it can be changed into a prime (211222111) 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, 9600995 + ... + 9601016.

It is an arithmetic number, because the mean of its divisors is an integer number (57606036).

Almost surely, 2^211222121 is an apocalyptic number.

It is an amenable number.

211222121 is a deficient number, since it is larger than the sum of its proper divisors (19202023).

211222121 is a wasteful number, since it uses less digits than its factorization.

211222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19202022.

The product of its digits is 32, while the sum is 14.

The square root of 211222121 is about 14533.4827553481. The cubic root of 211222121 is about 595.5430120388.

Adding to 211222121 its reverse (121222112), we get a palindrome (332444233).

Subtracting from 211222121 its reverse (121222112), we obtain a palindrome (90000009).

The spelling of 211222121 in words is "two hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".