20121221220000 has 480 divisors, whose sum is σ = 66291244411392. Its totient is φ = 5342182272000.

The previous prime is 20121221219999. The next prime is 20121221220017. The reversal of 20121221220000 is 2212212102.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 22787339559 + ... + 22787340441.

Almost surely, 2^{20121221220000} is an apocalyptic number.

20121221220000 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 20121221220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33145622205696).

20121221220000 is an abundant number, since it is smaller than the sum of its proper divisors (46170023191392).

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

20121221220000 is an equidigital number, since it uses as much as digits as its factorization.

20121221220000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2150 (or 2127 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 20121221220000 its reverse (2212212102), we get a palindrome (20123433432102).

The spelling of 20121221220000 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand".