21111100101112 has 128 divisors (see below), whose sum is σ = 46068955545600. Its totient is φ = 8883110320128.

The previous prime is 21111100101107. The next prime is 21111100101127. The reversal of 21111100101112 is 21110100111112.

It is a junction number, because it is equal to n+sod(n) for n = 21111100101092 and 21111100101101.

It is a congruent number.

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, 639268233 + ... + 639301255.

It is an arithmetic number, because the mean of its divisors is an integer number (359913715200).

Almost surely, 2^{21111100101112} 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 21111100101112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23034477772800).

21111100101112 is an abundant number, since it is smaller than the sum of its proper divisors (24957855444488).

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

21111100101112 is a wasteful number, since it uses less digits than its factorization.

21111100101112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34085 (or 34081 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21111100101112 its reverse (21110100111112), we get a palindrome (42221200212224).

The spelling of 21111100101112 in words is "twenty-one trillion, one hundred eleven billion, one hundred million, one hundred one thousand, one hundred twelve".