201221111121 has 8 divisors (see below), whose sum is σ = 271970086560. Its totient is φ = 132309771552.

The previous prime is 201221111107. The next prime is 201221111137. The reversal of 201221111121 is 121111122102.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 201221111121 - 2²⁷ = 201086893393 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 201221111121.

It is not an unprimeable number, because it can be changed into a prime (201221111621) 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 7 ways as a sum of consecutive naturals, for example, 459408711 + ... + 459409148.

It is an arithmetic number, because the mean of its divisors is an integer number (33996260820).

Almost surely, 2^201221111121 is an apocalyptic number.

It is an amenable number.

201221111121 is a deficient number, since it is larger than the sum of its proper divisors (70748975439).

201221111121 is an equidigital number, since it uses as much as digits as its factorization.

201221111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918817935.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 201221111121 its reverse (121111122102), we get a palindrome (322332233223).

The spelling of 201221111121 in words is "two hundred one billion, two hundred twenty-one million, one hundred eleven thousand, one hundred twenty-one".