2211222121 has 4 divisors (see below), whose sum is σ = 2212517700. Its totient is φ = 2209926544.

The previous prime is 2211222103. The next prime is 2211222137. The reversal of 2211222121 is 1212221122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 317231721 + 1893990400 = 17811^2 + 43520^2 .

It is a cyclic number.

It is not a de Polignac number, because 2211222121 - 2¹³ = 2211213929 is a prime.

It is a super-3 number, since 3×2211222121³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2211222095 and 2211222104.

It is not an unprimeable number, because it can be changed into a prime (2211222191) 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, 645226 + ... + 648643.

It is an arithmetic number, because the mean of its divisors is an integer number (553129425).

Almost surely, 2^2211222121 is an apocalyptic number.

It is an amenable number.

2211222121 is a deficient number, since it is larger than the sum of its proper divisors (1295579).

2211222121 is a wasteful number, since it uses less digits than its factorization.

2211222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1295578.

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

The square root of 2211222121 is about 47023.6336430948. The cubic root of 2211222121 is about 1302.7991207630.

Adding to 2211222121 its reverse (1212221122), we get a palindrome (3423443243).

Subtracting from 2211222121 its reverse (1212221122), we obtain a palindrome (999000999).

The spelling of 2211222121 in words is "two billion, two hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".