12122221312 has 72 divisors (see below), whose sum is σ = 25585156800. Its totient is φ = 5716288512.

The previous prime is 12122221303. The next prime is 12122221313. The reversal of 12122221312 is 21312222121.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 12122221312.

It is not an unprimeable number, because it can be changed into a prime (12122221313) 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 7 ways as a sum of consecutive naturals, for example, 1098639 + ... + 1109617.

It is an arithmetic number, because the mean of its divisors is an integer number (355349400).

Almost surely, 2^12122221312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12122221312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12792578400).

12122221312 is an abundant number, since it is smaller than the sum of its proper divisors (13462935488).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12122221312 is a wasteful number, since it uses less digits than its factorization.

12122221312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11241 (or 11227 counting only the distinct ones).

The product of its digits is 192, while the sum is 19.

Adding to 12122221312 its reverse (21312222121), we get a palindrome (33434443433).

The spelling of 12122221312 in words is "twelve billion, one hundred twenty-two million, two hundred twenty-one thousand, three hundred twelve".