12121122221 has 8 divisors (see below), whose sum is σ = 13054414464. Its totient is φ = 11187958320.

The previous prime is 12121122203. The next prime is 12121122229. The reversal of 12121122221 is 12222112121.

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 12121122221 - 2²² = 12116927917 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12121122221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121122229) 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 7 ways as a sum of consecutive naturals, for example, 268256 + ... + 310166.

It is an arithmetic number, because the mean of its divisors is an integer number (1631801808).

Almost surely, 2^12121122221 is an apocalyptic number.

It is an amenable number.

12121122221 is a deficient number, since it is larger than the sum of its proper divisors (933292243).

12121122221 is a wasteful number, since it uses less digits than its factorization.

12121122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64171.

The product of its digits is 64, while the sum is 17.

Adding to 12121122221 its reverse (12222112121), we get a palindrome (24343234342).

The spelling of 12121122221 in words is "twelve billion, one hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".