221111120121210 has 256 divisors, whose sum is σ = 666064766707200. Its totient is φ = 51703616563200.

The previous prime is 221111120121163. The next prime is 221111120121217. The reversal of 221111120121210 is 12121021111122.

It is a happy number.

221111120121210 is a `hidden beast` number, since 2 + 211 + 1 + 1 + 120 + 121 + 210 = 666.

221111120121210 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (221111120121217) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 86681542 + ... + 89195918.

It is an arithmetic number, because the mean of its divisors is an integer number (2601815494950).

Almost surely, 2^{221111120121210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221111120121210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (333032383353600).

221111120121210 is an abundant number, since it is smaller than the sum of its proper divisors (444953646585990).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221111120121210 is a wasteful number, since it uses less digits than its factorization.

221111120121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2515454 (or 2515448 counting only the distinct ones).

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

Adding to 221111120121210 its reverse (12121021111122), we get a palindrome (233232141232332).

The spelling of 221111120121210 in words is "two hundred twenty-one trillion, one hundred eleven billion, one hundred twenty million, one hundred twenty-one thousand, two hundred ten".