21320120111100 has 72 divisors (see below), whose sum is σ = 61733776004208. Its totient is φ = 5680981785600.

The previous prime is 21320120111063. The next prime is 21320120111107. The reversal of 21320120111100 is 111102102312.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21320120111100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320120111107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27007611 + ... + 27785810.

It is an arithmetic number, because the mean of its divisors is an integer number (857413555614).

Almost surely, 2^{21320120111100} is an apocalyptic number.

21320120111100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21320120111100 is an abundant number, since it is smaller than the sum of its proper divisors (40413655893108).

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

21320120111100 is a wasteful number, since it uses less digits than its factorization.

21320120111100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54794735 (or 54794728 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21320120111100 its reverse (111102102312), we get a palindrome (21431222213412).

The spelling of 21320120111100 in words is "twenty-one trillion, three hundred twenty billion, one hundred twenty million, one hundred eleven thousand, one hundred".