2112222121 has 4 divisors (see below), whose sum is σ = 2119014144. Its totient is φ = 2105430100.

The previous prime is 2112222113. The next prime is 2112222127. The reversal of 2112222121 is 1212222112.

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 2112222121 - 2³ = 2112222113 is a prime.

It is a super-2 number, since 2×2112222121² = 8922964576883477282, 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 = 2112222095 and 2112222104.

It is not an unprimeable number, because it can be changed into a prime (2112222127) 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, 3395545 + ... + 3396166.

It is an arithmetic number, because the mean of its divisors is an integer number (529753536).

Almost surely, 2^2112222121 is an apocalyptic number.

It is an amenable number.

2112222121 is a deficient number, since it is larger than the sum of its proper divisors (6792023).

2112222121 is an equidigital number, since it uses as much as digits as its factorization.

2112222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6792022.

The product of its digits is 64, while the sum is 16.

The square root of 2112222121 is about 45958.9177527061. The cubic root of 2112222121 is about 1283.0587090032.

Adding to 2112222121 its reverse (1212222112), we get a palindrome (3324444233).

Subtracting from 2112222121 its reverse (1212222112), we obtain a palindrome (900000009).

The spelling of 2112222121 in words is "two billion, one hundred twelve million, two hundred twenty-two thousand, one hundred twenty-one".