21011220111112 has 128 divisors (see below), whose sum is σ = 50100619944960. Its totient is φ = 8022626277120.

The previous prime is 21011220111097. The next prime is 21011220111143. The reversal of 21011220111112 is 21111102211012.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28463763 + ... + 29192605.

It is an arithmetic number, because the mean of its divisors is an integer number (391411093320).

Almost surely, 2^{21011220111112} is an apocalyptic number.

21011220111112 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 21011220111112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25050309972480).

21011220111112 is an abundant number, since it is smaller than the sum of its proper divisors (29089399833848).

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

21011220111112 is a wasteful number, since it uses less digits than its factorization.

21011220111112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729803 (or 729799 counting only the distinct ones).

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

Adding to 21011220111112 its reverse (21111102211012), we get a palindrome (42122322322124).

The spelling of 21011220111112 in words is "twenty-one trillion, eleven billion, two hundred twenty million, one hundred eleven thousand, one hundred twelve".