12321221220 has 288 divisors, whose sum is σ = 46708945920. Its totient is φ = 2554087680.

The previous prime is 12321221207. The next prime is 12321221249. The reversal of 12321221220 is 2212212321.

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 = 12321221193 and 12321221202.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7802391 + ... + 7803969.

It is an arithmetic number, because the mean of its divisors is an integer number (162183840).

Almost surely, 2^12321221220 is an apocalyptic number.

12321221220 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 12321221220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23354472960).

12321221220 is an abundant number, since it is smaller than the sum of its proper divisors (34387724700).

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

12321221220 is a wasteful number, since it uses less digits than its factorization.

12321221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2175 (or 2170 counting only the distinct ones).

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

Adding to 12321221220 its reverse (2212212321), we get a palindrome (14533433541).

The spelling of 12321221220 in words is "twelve billion, three hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty".