20121221120 has 576 divisors, whose sum is σ = 65610155520. Its totient is φ = 5750784000.

The previous prime is 20121221117. The next prime is 20121221129. The reversal of 20121221120 is 2112212102.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 20121221095 and 20121221104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121221129) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 133253045 + ... + 133253195.

It is an arithmetic number, because the mean of its divisors is an integer number (113906520).

Almost surely, 2^20121221120 is an apocalyptic number.

20121221120 is a gapful number since it is divisible by the number (20) 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 20121221120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32805077760).

20121221120 is an abundant number, since it is smaller than the sum of its proper divisors (45488934400).

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

20121221120 is a wasteful number, since it uses less digits than its factorization.

20121221120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 189 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20121221120 its reverse (2112212102), we get a palindrome (22233433222).

The spelling of 20121221120 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred twenty".