21201221202112 has 112 divisors (see below), whose sum is σ = 48163404377088. Its totient is φ = 9070741370880.

The previous prime is 21201221202089. The next prime is 21201221202127. The reversal of 21201221202112 is 21120212210212.

It is a tau number, because it is divible by the number of its divisors (112).

It is a self number, because there is not a number n which added to its sum of digits gives 21201221202112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 762866937 + ... + 762894727.

It is an arithmetic number, because the mean of its divisors is an integer number (430030396224).

Almost surely, 2^{21201221202112} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21201221202112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24081702188544).

21201221202112 is an abundant number, since it is smaller than the sum of its proper divisors (26962183174976).

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

21201221202112 is a wasteful number, since it uses less digits than its factorization.

21201221202112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30654 (or 30644 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21201221202112 its reverse (21120212210212), we get a palindrome (42321433412324).

The spelling of 21201221202112 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-one million, two hundred two thousand, one hundred twelve".