221211121321 has 4 divisors (see below), whose sum is σ = 222334020612. Its totient is φ = 220088222032.

The previous prime is 221211121303. The next prime is 221211121393. The reversal of 221211121321 is 123121112122.

221211121321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123121112122 = 2 ⋅61560556061.

It can be written as a sum of positive squares in 2 ways, for example, as 219057697296 + 2153424025 = 468036^2 + 46405^2 .

It is a cyclic number.

It is not a de Polignac number, because 221211121321 - 2¹⁹ = 221210597033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221211161321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561449350 + ... + 561449743.

It is an arithmetic number, because the mean of its divisors is an integer number (55583505153).

Almost surely, 2^221211121321 is an apocalyptic number.

It is an amenable number.

221211121321 is a deficient number, since it is larger than the sum of its proper divisors (1122899291).

221211121321 is a wasteful number, since it uses less digits than its factorization.

221211121321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122899290.

The product of its digits is 96, while the sum is 19.

Adding to 221211121321 its reverse (123121112122), we get a palindrome (344332233443).

The spelling of 221211121321 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred twenty-one thousand, three hundred twenty-one".