21112102121121 has 24 divisors (see below), whose sum is σ = 34713970289856. Its totient is φ = 12238899779040.

The previous prime is 21112102121101. The next prime is 21112102121129. The reversal of 21112102121121 is 12112120121112.

It is a happy number.

21112102121121 is a `hidden beast` number, since 211 + 1 + 210 + 2 + 121 + 121 = 666.

It is not a de Polignac number, because 21112102121121 - 2¹⁵ = 21112102088353 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112102121094 and 21112102121103.

It is not an unprimeable number, because it can be changed into a prime (21112102121129) 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 23 ways as a sum of consecutive naturals, for example, 4635944610 + ... + 4635949163.

It is an arithmetic number, because the mean of its divisors is an integer number (1446415428744).

Almost surely, 2^{21112102121121} is an apocalyptic number.

It is an amenable number.

21112102121121 is a deficient number, since it is larger than the sum of its proper divisors (13601868168735).

21112102121121 is a wasteful number, since it uses less digits than its factorization.

21112102121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9271893813 (or 9271893810 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21112102121121 its reverse (12112120121112), we get a palindrome (33224222242233).

Subtracting from 21112102121121 its reverse (12112120121112), we obtain a square (8999982000009 = 2999997²).

The spelling of 21112102121121 in words is "twenty-one trillion, one hundred twelve billion, one hundred two million, one hundred twenty-one thousand, one hundred twenty-one".