12221211220 has 96 divisors (see below), whose sum is σ = 26930534400. Its totient is φ = 4653158400.

The previous prime is 12221211203. The next prime is 12221211227. The reversal of 12221211220 is 2211212221.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 12221211194 and 12221211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221211227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13297921 + ... + 13298839.

It is an arithmetic number, because the mean of its divisors is an integer number (280526400).

Almost surely, 2^12221211220 is an apocalyptic number.

12221211220 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 12221211220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13465267200).

12221211220 is an abundant number, since it is smaller than the sum of its proper divisors (14709323180).

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

12221211220 is a wasteful number, since it uses less digits than its factorization.

12221211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1289 (or 1287 counting only the distinct ones).

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

Adding to 12221211220 its reverse (2211212221), we get a palindrome (14432423441).

The spelling of 12221211220 in words is "twelve billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty".