12121223220 has 144 divisors (see below), whose sum is σ = 37205034048. Its totient is φ = 3194042880.

The previous prime is 12121223209. The next prime is 12121223263. The reversal of 12121223220 is 2232212121.

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

It is a junction number, because it is equal to n+sod(n) for n = 12121223193 and 12121223202.

It is a congruent number.

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, 14656447 + ... + 14657273.

It is an arithmetic number, because the mean of its divisors is an integer number (258368292).

Almost surely, 2^12121223220 is an apocalyptic number.

12121223220 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 12121223220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18602517024).

12121223220 is an abundant number, since it is smaller than the sum of its proper divisors (25083810828).

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

12121223220 is a wasteful number, since it uses less digits than its factorization.

12121223220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1710 (or 1705 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 12121223220 its reverse (2232212121), we get a palindrome (14353435341).

The spelling of 12121223220 in words is "twelve billion, one hundred twenty-one million, two hundred twenty-three thousand, two hundred twenty".