12122121220 has 144 divisors (see below), whose sum is σ = 30472747200. Its totient is φ = 4031596800.

The previous prime is 12122121203. The next prime is 12122121233. The reversal of 12122121220 is 2212122121.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 12122121194 and 12122121203.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1328875 + ... + 1337965.

It is an arithmetic number, because the mean of its divisors is an integer number (211616300).

Almost surely, 2^12122121220 is an apocalyptic number.

12122121220 is a gapful number since it is divisible by the number (10) 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 12122121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15236373600).

12122121220 is an abundant number, since it is smaller than the sum of its proper divisors (18350625980).

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

12122121220 is a wasteful number, since it uses less digits than its factorization.

12122121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9170 (or 9157 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 12122121220 its reverse (2212122121), we get a palindrome (14334243341).

Subtracting from 12122121220 its reverse (2212122121), we obtain a palindrome (9909999099).

The spelling of 12122121220 in words is "twelve billion, one hundred twenty-two million, one hundred twenty-one thousand, two hundred twenty".