210111110021 has 4 divisors (see below), whose sum is σ = 212471909100. Its totient is φ = 207750310944.

The previous prime is 210111110009. The next prime is 210111110023. The reversal of 210111110021 is 120011111012.

210111110021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 142703373121 + 67407736900 = 377761^2 + 259630^2 .

It is a cyclic number.

It is not a de Polignac number, because 210111110021 - 2¹⁰ = 210111108997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210111109984 and 210111110011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210111110023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1180399406 + ... + 1180399583.

It is an arithmetic number, because the mean of its divisors is an integer number (53117977275).

Almost surely, 2^210111110021 is an apocalyptic number.

It is an amenable number.

210111110021 is a deficient number, since it is larger than the sum of its proper divisors (2360799079).

210111110021 is an equidigital number, since it uses as much as digits as its factorization.

210111110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2360799078.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 210111110021 its reverse (120011111012), we get a palindrome (330122221033).

Subtracting from 210111110021 its reverse (120011111012), we obtain a palindrome (90099999009).

The spelling of 210111110021 in words is "two hundred ten billion, one hundred eleven million, one hundred ten thousand, twenty-one".