20211221131200 has 1344 divisors, whose sum is σ = 84900234608640. Its totient is φ = 4631219712000.

The previous prime is 20211221131177. The next prime is 20211221131207. The reversal of 20211221131200 is 213112211202.

20211221131200 is a `hidden beast` number, since 2 + 0 + 211 + 221 + 1 + 31 + 200 = 666.

It is a super-2 number, since 2×20211221131200² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211221131207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 633425647 + ... + 633457553.

Almost surely, 2^{20211221131200} is an apocalyptic number.

20211221131200 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 20211221131200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42450117304320).

20211221131200 is an abundant number, since it is smaller than the sum of its proper divisors (64689013477440).

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

20211221131200 is a wasteful number, since it uses less digits than its factorization.

20211221131200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32023 (or 32002 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 20211221131200 its reverse (213112211202), we get a palindrome (20424333342402).

It can be divided in two parts, 202112 and 21131200, that added together give a palindrome (21333312).

The spelling of 20211221131200 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-one million, one hundred thirty-one thousand, two hundred".