11211211022221 has 4 divisors (see below), whose sum is σ = 12812812596832. Its totient is φ = 9609609447612.

The previous prime is 11211211022191. The next prime is 11211211022227. The reversal of 11211211022221 is 12222011211211.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11211211022221 - 2⁵ = 11211211022189 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 (11211211022227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 800800787295 + ... + 800800787308.

It is an arithmetic number, because the mean of its divisors is an integer number (3203203149208).

Almost surely, 2^{11211211022221} is an apocalyptic number.

It is an amenable number.

11211211022221 is a deficient number, since it is larger than the sum of its proper divisors (1601601574611).

11211211022221 is an equidigital number, since it uses as much as digits as its factorization.

11211211022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1601601574610.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 11211211022221 its reverse (12222011211211), we get a palindrome (23433222233432).

The spelling of 11211211022221 in words is "eleven trillion, two hundred eleven billion, two hundred eleven million, twenty-two thousand, two hundred twenty-one".