201221111222101 has 2 divisors, whose sum is σ = 201221111222102. Its totient is φ = 201221111222100.

The previous prime is 201221111222077. The next prime is 201221111222213. The reversal of 201221111222101 is 101222111122102.

It is a happy number.

201221111222101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 183636918612900 + 17584192609201 = 13551270^2 + 4193351^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221111222101 - 2¹⁵ = 201221111189333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201221111232101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100610555611050 + 100610555611051.

It is an arithmetic number, because the mean of its divisors is an integer number (100610555611051).

Almost surely, 2^{201221111222101} is an apocalyptic number.

It is an amenable number.

201221111222101 is a deficient number, since it is larger than the sum of its proper divisors (1).

201221111222101 is an equidigital number, since it uses as much as digits as its factorization.

201221111222101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 201221111222101 its reverse (101222111122102), we get a palindrome (302443222344203).

Subtracting from 201221111222101 its reverse (101222111122102), we obtain a palindrome (99999000099999).

The spelling of 201221111222101 in words is "two hundred one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred twenty-two thousand, one hundred one".