12122121221 has 12 divisors (see below), whose sum is σ = 14107385088. Its totient is φ = 10385863992.

The previous prime is 12122121203. The next prime is 12122121233. The reversal of 12122121221 is 12212122121.

It is not a de Polignac number, because 12122121221 - 2⁶ = 12122121157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12122121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12122121421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62300 + ... + 167706.

It is an arithmetic number, because the mean of its divisors is an integer number (1175615424).

Almost surely, 2^12122121221 is an apocalyptic number.

It is an amenable number.

12122121221 is a deficient number, since it is larger than the sum of its proper divisors (1985263867).

12122121221 is a wasteful number, since it uses less digits than its factorization.

12122121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107768 (or 107761 counting only the distinct ones).

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

Adding to 12122121221 its reverse (12212122121), we get a palindrome (24334243342).

The spelling of 12122121221 in words is "twelve billion, one hundred twenty-two million, one hundred twenty-one thousand, two hundred twenty-one".