221220211121 has 8 divisors (see below), whose sum is σ = 272271029184. Its totient is φ = 175031375760.

The previous prime is 221220211063. The next prime is 221220211153. The reversal of 221220211121 is 121112022122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221220211121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221220211121.

It is not an unprimeable number, because it can be changed into a prime (221220211921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1215495575 + ... + 1215495756.

It is an arithmetic number, because the mean of its divisors is an integer number (34033878648).

Almost surely, 2^221220211121 is an apocalyptic number.

It is an amenable number.

221220211121 is a deficient number, since it is larger than the sum of its proper divisors (51050818063).

221220211121 is a wasteful number, since it uses less digits than its factorization.

221220211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2430991351.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221220211121 its reverse (121112022122), we get a palindrome (342332233243).

The spelling of 221220211121 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred eleven thousand, one hundred twenty-one".