11112221221 has 4 divisors (see below), whose sum is σ = 11294388844. Its totient is φ = 10930053600.

The previous prime is 11112221213. The next prime is 11112221227. The reversal of 11112221221 is 12212221111.

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 2941869121 + 8170352100 = 54239^2 + 90390^2 .

It is a cyclic number.

It is not a de Polignac number, because 11112221221 - 2³ = 11112221213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11112221195 and 11112221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11112221227) 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, 91083720 + ... + 91083841.

It is an arithmetic number, because the mean of its divisors is an integer number (2823597211).

Almost surely, 2^11112221221 is an apocalyptic number.

It is an amenable number.

11112221221 is a deficient number, since it is larger than the sum of its proper divisors (182167623).

11112221221 is an equidigital number, since it uses as much as digits as its factorization.

11112221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182167622.

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

Adding to 11112221221 its reverse (12212221111), we get a palindrome (23324442332).

The spelling of 11112221221 in words is "eleven billion, one hundred twelve million, two hundred twenty-one thousand, two hundred twenty-one".