2101222121 has 2 divisors, whose sum is σ = 2101222122. Its totient is φ = 2101222120.

The previous prime is 2101222111. The next prime is 2101222163. The reversal of 2101222121 is 1212221012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1250683225 + 850538896 = 35365^2 + 29164^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101222121 - 2²² = 2097027817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2101222096 and 2101222105.

It is not a weakly prime, because it can be changed into another prime (2101222111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050611060 + 1050611061.

It is an arithmetic number, because the mean of its divisors is an integer number (1050611061).

Almost surely, 2^2101222121 is an apocalyptic number.

It is an amenable number.

2101222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101222121 is an equidigital number, since it uses as much as digits as its factorization.

2101222121 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2101222121 is about 45839.0894433997. The cubic root of 2101222121 is about 1280.8275331134.

Adding to 2101222121 its reverse (1212221012), we get a palindrome (3313443133).

The spelling of 2101222121 in words is "two billion, one hundred one million, two hundred twenty-two thousand, one hundred twenty-one".