11221121221 has 4 divisors (see below), whose sum is σ = 11221756000. Its totient is φ = 11220486444.

The previous prime is 11221121209. The next prime is 11221121237. The reversal of 11221121221 is 12212112211.

11221121221 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11221121221 is a prime.

It is a super-2 number, since 2×11221121221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11221121195 and 11221121204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11221121291) 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, 290091 + ... + 326488.

It is an arithmetic number, because the mean of its divisors is an integer number (2805439000).

Almost surely, 2^11221121221 is an apocalyptic number.

It is an amenable number.

11221121221 is a deficient number, since it is larger than the sum of its proper divisors (634779).

11221121221 is an equidigital number, since it uses as much as digits as its factorization.

11221121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 634778.

The product of its digits is 32, while the sum is 16.

Adding to 11221121221 its reverse (12212112211), we get a palindrome (23433233432).

The spelling of 11221121221 in words is "eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".