210111111012221 has 6 divisors (see below), whose sum is σ = 221751615777822. Its totient is φ = 199052631484920.

The previous prime is 210111111012191. The next prime is 210111111012247. The reversal of 210111111012221 is 122210111111012.

It can be written as a sum of positive squares in only one way, i.e., 209994471686596 + 116639325625 = 14491186^2 + 341525^2 .

It is not a de Polignac number, because 210111111012221 - 2²⁶ = 210111043903357 is a prime.

It is a super-2 number, since 2×210111111012221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 210111111012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210111111012721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 291012618770 + ... + 291012619491.

It is an arithmetic number, because the mean of its divisors is an integer number (36958602629637).

Almost surely, 2^{210111111012221} is an apocalyptic number.

It is an amenable number.

210111111012221 is a deficient number, since it is larger than the sum of its proper divisors (11640504765601).

210111111012221 is an equidigital number, since it uses as much as digits as its factorization.

210111111012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582025238299 (or 582025238280 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 210111111012221 its reverse (122210111111012), we get a palindrome (332321222123233).

The spelling of 210111111012221 in words is "two hundred ten trillion, one hundred eleven billion, one hundred eleven million, twelve thousand, two hundred twenty-one".