21112012221121 has 4 divisors (see below), whose sum is σ = 21251826871744. Its totient is φ = 20972197570500.

The previous prime is 21112012221073. The next prime is 21112012221143. The reversal of 21112012221121 is 12112221021112.

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 21112012221121 - 2¹⁷ = 21112012090049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112012228121) 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 3 ways as a sum of consecutive naturals, for example, 69907325085 + ... + 69907325386.

It is an arithmetic number, because the mean of its divisors is an integer number (5312956717936).

Almost surely, 2^{21112012221121} is an apocalyptic number.

It is an amenable number.

21112012221121 is a deficient number, since it is larger than the sum of its proper divisors (139814650623).

21112012221121 is a wasteful number, since it uses less digits than its factorization.

21112012221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139814650622.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21112012221121 its reverse (12112221021112), we get a palindrome (33224233242233).

The spelling of 21112012221121 in words is "twenty-one trillion, one hundred twelve billion, twelve million, two hundred twenty-one thousand, one hundred twenty-one".