11221212121 has 24 divisors (see below), whose sum is σ = 13634637120. Its totient is φ = 9196240032.

The previous prime is 11221212097. The next prime is 11221212131. The reversal of 11221212121 is 12121212211.

It is not a de Polignac number, because 11221212121 - 2¹¹ = 11221210073 is a prime.

It is a Duffinian number.

11221212121 is a modest number, since divided by 212121 gives 11221 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 11221212095 and 11221212104.

It is not an unprimeable number, because it can be changed into a prime (11221212131) 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 23 ways as a sum of consecutive naturals, for example, 108030 + ... + 184696.

It is an arithmetic number, because the mean of its divisors is an integer number (568109880).

Almost surely, 2^11221212121 is an apocalyptic number.

It is an amenable number.

11221212121 is a deficient number, since it is larger than the sum of its proper divisors (2413424999).

11221212121 is a wasteful number, since it uses less digits than its factorization.

11221212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76813 (or 76806 counting only the distinct ones).

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

Adding to 11221212121 its reverse (12121212211), we get a palindrome (23342424332).

The spelling of 11221212121 in words is "eleven billion, two hundred twenty-one million, two hundred twelve thousand, one hundred twenty-one".