12121122112221 has 16 divisors (see below), whose sum is σ = 16864304688000. Its totient is φ = 7729349422080.

The previous prime is 12121122112213. The next prime is 12121122112247. The reversal of 12121122112221 is 12221122112121.

It is not a de Polignac number, because 12121122112221 - 2³ = 12121122112213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121122112621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8947405 + ... + 10212653.

It is an arithmetic number, because the mean of its divisors is an integer number (1054019043000).

Almost surely, 2^{12121122112221} is an apocalyptic number.

It is an amenable number.

12121122112221 is a deficient number, since it is larger than the sum of its proper divisors (4743182575779).

12121122112221 is a wasteful number, since it uses less digits than its factorization.

12121122112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404116.

The product of its digits is 128, while the sum is 21.

Adding to 12121122112221 its reverse (12221122112121), we get a palindrome (24342244224342).

The spelling of 12121122112221 in words is "twelve trillion, one hundred twenty-one billion, one hundred twenty-two million, one hundred twelve thousand, two hundred twenty-one".