16111122210221 has 4 divisors (see below), whose sum is σ = 16111363270332. Its totient is φ = 16110881150112.

The previous prime is 16111122210107. The next prime is 16111122210233. The reversal of 16111122210221 is 12201222111161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10006220154121 + 6104902056100 = 3163261^2 + 2470810^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16111122210221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16111122210721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120429776 + ... + 120563481.

It is an arithmetic number, because the mean of its divisors is an integer number (4027840817583).

Almost surely, 2^{16111122210221} is an apocalyptic number.

It is an amenable number.

16111122210221 is a deficient number, since it is larger than the sum of its proper divisors (241060111).

16111122210221 is an equidigital number, since it uses as much as digits as its factorization.

16111122210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241060110.

The product of its (nonzero) digits is 192, while the sum is 23.

Adding to 16111122210221 its reverse (12201222111161), we get a palindrome (28312344321382).

The spelling of 16111122210221 in words is "sixteen trillion, one hundred eleven billion, one hundred twenty-two million, two hundred ten thousand, two hundred twenty-one".