21020111112 has 256 divisors, whose sum is σ = 71263825920. Its totient is φ = 4989312000.

The previous prime is 21020111111. The next prime is 21020111153. The reversal of 21020111112 is 21111102012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (21020111111) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2422093 + ... + 2430755.

It is an arithmetic number, because the mean of its divisors is an integer number (278374320).

Almost surely, 2^21020111112 is an apocalyptic number.

21020111112 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 21020111112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35631912960).

21020111112 is an abundant number, since it is smaller than the sum of its proper divisors (50243714808).

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

21020111112 is a wasteful number, since it uses less digits than its factorization.

21020111112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8804 (or 8800 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21020111112 its reverse (21111102012), we get a palindrome (42131213124).

The spelling of 21020111112 in words is "twenty-one billion, twenty million, one hundred eleven thousand, one hundred twelve".