21200111121112 has 128 divisors (see below), whose sum is σ = 49865206809600. Its totient is φ = 8208759283200.

The previous prime is 21200111121061. The next prime is 21200111121131. The reversal of 21200111121112 is 21112111100212.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 171976714 + ... + 172099942.

It is an arithmetic number, because the mean of its divisors is an integer number (389571928200).

Almost surely, 2^{21200111121112} is an apocalyptic number.

21200111121112 is a gapful number since it is divisible by the number (22) 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 21200111121112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24932603404800).

21200111121112 is an abundant number, since it is smaller than the sum of its proper divisors (28665095688488).

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

21200111121112 is a wasteful number, since it uses less digits than its factorization.

21200111121112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124977 (or 124973 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21200111121112 its reverse (21112111100212), we get a palindrome (42312222221324).

The spelling of 21200111121112 in words is "twenty-one trillion, two hundred billion, one hundred eleven million, one hundred twenty-one thousand, one hundred twelve".