2112212121221 has 16 divisors (see below), whose sum is σ = 2138352156864. Its totient is φ = 2086164570624.

The previous prime is 2112212121197. The next prime is 2112212121233. The reversal of 2112212121221 is 1221212122112.

It is a cyclic number.

It is not a de Polignac number, because 2112212121221 - 2⁶ = 2112212121157 is a prime.

It is a super-2 number, since 2×2112212121221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2112212121193 and 2112212121202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2112212121241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142066430 + ... + 142081296.

It is an arithmetic number, because the mean of its divisors is an integer number (133647009804).

Almost surely, 2^{2112212121221} is an apocalyptic number.

It is an amenable number.

2112212121221 is a deficient number, since it is larger than the sum of its proper divisors (26140035643).

2112212121221 is a wasteful number, since it uses less digits than its factorization.

2112212121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17860.

The product of its digits is 128, while the sum is 20.

Adding to 2112212121221 its reverse (1221212122112), we get a palindrome (3333424243333).

The spelling of 2112212121221 in words is "two trillion, one hundred twelve billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".