221101212112121 has 16 divisors (see below), whose sum is σ = 241478432211840. Its totient is φ = 200770203553920.

The previous prime is 221101212112019. The next prime is 221101212112349. The reversal of 221101212112121 is 121211212101122.

It is a happy number.

It is not a de Polignac number, because 221101212112121 - 2¹⁴ = 221101212095737 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221101212112093 and 221101212112102.

It is not an unprimeable number, because it can be changed into a prime (221101212112421) 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 15 ways as a sum of consecutive naturals, for example, 168094421 + ... + 169404653.

It is an arithmetic number, because the mean of its divisors is an integer number (15092402013240).

Almost surely, 2^{221101212112121} is an apocalyptic number.

It is an amenable number.

221101212112121 is a deficient number, since it is larger than the sum of its proper divisors (20377220099719).

221101212112121 is a wasteful number, since it uses less digits than its factorization.

221101212112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1327856.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 221101212112121 its reverse (121211212101122), we get a palindrome (342312424213243).

It can be divided in two parts, 22110121 and 2112121, that added together give a palindrome (24222242).

The spelling of 221101212112121 in words is "two hundred twenty-one trillion, one hundred one billion, two hundred twelve million, one hundred twelve thousand, one hundred twenty-one".