21111222103121 has 4 divisors (see below), whose sum is σ = 21320244104244. Its totient is φ = 20902200102000.

The previous prime is 21111222103109. The next prime is 21111222103129. The reversal of 21111222103121 is 12130122211112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18394972012096 + 2716250091025 = 4288936^2 + 1648105^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111222103121 - 2⁶ = 21111222103057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111222103093 and 21111222103102.

It is not an unprimeable number, because it can be changed into a prime (21111222103129) 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, 104511000410 + ... + 104511000611.

It is an arithmetic number, because the mean of its divisors is an integer number (5330061026061).

Almost surely, 2^{21111222103121} is an apocalyptic number.

It is an amenable number.

21111222103121 is a deficient number, since it is larger than the sum of its proper divisors (209022001123).

21111222103121 is a wasteful number, since it uses less digits than its factorization.

21111222103121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209022001122.

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 21111222103121 its reverse (12130122211112), we get a palindrome (33241344314233).

The spelling of 21111222103121 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, one hundred three thousand, one hundred twenty-one".