2112201212221 has 4 divisors (see below), whose sum is σ = 2112425995612. Its totient is φ = 2111976428832.

The previous prime is 2112201212201. The next prime is 2112201212239. The reversal of 2112201212221 is 1222121022112.

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 211359948121 + 1900841264100 = 459739^2 + 1378710^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2112201212221 is a prime.

It is a super-2 number, since 2×2112201212221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2112201212201) 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 in 3 ways as a sum of consecutive naturals, for example, 112377600 + ... + 112396393.

It is an arithmetic number, because the mean of its divisors is an integer number (528106498903).

Almost surely, 2^{2112201212221} is an apocalyptic number.

It is an amenable number.

2112201212221 is a deficient number, since it is larger than the sum of its proper divisors (224783391).

2112201212221 is an equidigital number, since it uses as much as digits as its factorization.

2112201212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224783390.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 2112201212221 its reverse (1222121022112), we get a palindrome (3334322234333).

The spelling of 2112201212221 in words is "two trillion, one hundred twelve billion, two hundred one million, two hundred twelve thousand, two hundred twenty-one".