12122221212 has 288 divisors, whose sum is σ = 35713379520. Its totient is φ = 3576545280.

The previous prime is 12122221151. The next prime is 12122221219. The reversal of 12122221212 is 21212222121.

It is a happy number.

It is a super-2 number, since 2×12122221212² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12122221219) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 19646728 + ... + 19647344.

It is an arithmetic number, because the mean of its divisors is an integer number (124004790).

Almost surely, 2^12122221212 is an apocalyptic number.

12122221212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12122221212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17856689760).

12122221212 is an abundant number, since it is smaller than the sum of its proper divisors (23591158308).

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

12122221212 is a wasteful number, since it uses less digits than its factorization.

12122221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723 (or 709 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

Adding to 12122221212 its reverse (21212222121), we get a palindrome (33334443333).

Subtracting 12122221212 from its reverse (21212222121), we obtain a palindrome (9090000909).

It can be divided in two parts, 1212222121 and 2, that multiplied together give a palindrome (2424444242).

The spelling of 12122221212 in words is "twelve billion, one hundred twenty-two million, two hundred twenty-one thousand, two hundred twelve".