201221222011 has 4 divisors (see below), whose sum is σ = 201657711024. Its totient is φ = 200784733000.

The previous prime is 201221221997. The next prime is 201221222039. The reversal of 201221222011 is 110222122102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 110222122102 = 2 ⋅55111061051.

It is a cyclic number.

It is not a de Polignac number, because 201221222011 - 2⁹ = 201221221499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201221222051) 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, 218243815 + ... + 218244736.

It is an arithmetic number, because the mean of its divisors is an integer number (50414427756).

Almost surely, 2^201221222011 is an apocalyptic number.

201221222011 is a deficient number, since it is larger than the sum of its proper divisors (436489013).

201221222011 is an equidigital number, since it uses as much as digits as its factorization.

201221222011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436489012.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 201221222011 its reverse (110222122102), we get a palindrome (311443344113).

Subtracting from 201221222011 its reverse (110222122102), we obtain a palindrome (90999099909).

The spelling of 201221222011 in words is "two hundred one billion, two hundred twenty-one million, two hundred twenty-two thousand, eleven".