11121221221 has 8 divisors (see below), whose sum is σ = 12146992704. Its totient is φ = 10097908320.

The previous prime is 11121221203. The next prime is 11121221233. The reversal of 11121221221 is 12212212111.

11121221221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11121221221 - 2⁷ = 11121221093 is a prime.

It is a super-2 number, since 2×11121221221² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11121221195 and 11121221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11121221261) 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 7 ways as a sum of consecutive naturals, for example, 605176 + ... + 623281.

It is an arithmetic number, because the mean of its divisors is an integer number (1518374088).

Almost surely, 2^11121221221 is an apocalyptic number.

11121221221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11121221221 is a deficient number, since it is larger than the sum of its proper divisors (1025771483).

11121221221 is a wasteful number, since it uses less digits than its factorization.

11121221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1229291.

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

Adding to 11121221221 its reverse (12212212111), we get a palindrome (23333433332).

The spelling of 11121221221 in words is "eleven billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".