21112212121121 has 8 divisors (see below), whose sum is σ = 23169417332544. Its totient is φ = 19077992443120.

The previous prime is 21112212121093. The next prime is 21112212121141. The reversal of 21112212121121 is 12112121221112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21112212121121 - 2³⁰ = 21111138379297 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112212121093 and 21112212121102.

It is not an unprimeable number, because it can be changed into a prime (21112212121141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5746381430 + ... + 5746385103.

It is an arithmetic number, because the mean of its divisors is an integer number (2896177166568).

Almost surely, 2^{21112212121121} is an apocalyptic number.

It is an amenable number.

21112212121121 is a deficient number, since it is larger than the sum of its proper divisors (2057205211423).

21112212121121 is a wasteful number, since it uses less digits than its factorization.

21112212121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11492766711.

The product of its digits is 64, while the sum is 20.

Adding to 21112212121121 its reverse (12112121221112), we get a palindrome (33224333342233).

Subtracting from 21112212121121 its reverse (12112121221112), we obtain a palindrome (9000090900009).

The spelling of 21112212121121 in words is "twenty-one trillion, one hundred twelve billion, two hundred twelve million, one hundred twenty-one thousand, one hundred twenty-one".