21111020011121 has 32 divisors (see below), whose sum is σ = 21761275379712. Its totient is φ = 20468756790720.

The previous prime is 21111020011069. The next prime is 21111020011157. The reversal of 21111020011121 is 12111002011112.

It is a cyclic number.

It is not a de Polignac number, because 21111020011121 - 2⁶ = 21111020011057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111020011096 and 21111020011105.

It is not an unprimeable number, because it can be changed into a prime (21111020011721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3212752766 + ... + 3212759336.

It is an arithmetic number, because the mean of its divisors is an integer number (680039855616).

Almost surely, 2^{21111020011121} is an apocalyptic number.

It is an amenable number.

21111020011121 is a deficient number, since it is larger than the sum of its proper divisors (650255368591).

21111020011121 is a wasteful number, since it uses less digits than its factorization.

21111020011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7893.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21111020011121 its reverse (12111002011112), we get a palindrome (33222022022233).

Subtracting from 21111020011121 its reverse (12111002011112), we obtain a square (9000018000009 = 3000003²).

The spelling of 21111020011121 in words is "twenty-one trillion, one hundred eleven billion, twenty million, eleven thousand, one hundred twenty-one".