12111231220 has 72 divisors (see below), whose sum is σ = 28606308192. Its totient is φ = 4301626560.

The previous prime is 12111231211. The next prime is 12111231247. The reversal of 12111231220 is 2213211121.

It is a junction number, because it is equal to n+sod(n) for n = 12111231194 and 12111231203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45867 + ... + 162253.

It is an arithmetic number, because the mean of its divisors is an integer number (397309836).

Almost surely, 2^12111231220 is an apocalyptic number.

12111231220 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 12111231220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14303154096).

12111231220 is an abundant number, since it is smaller than the sum of its proper divisors (16495076972).

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

12111231220 is a wasteful number, since it uses less digits than its factorization.

12111231220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116461 (or 116448 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 12111231220 its reverse (2213211121), we get a palindrome (14324442341).

The spelling of 12111231220 in words is "twelve billion, one hundred eleven million, two hundred thirty-one thousand, two hundred twenty".