21112100111100 has 144 divisors (see below), whose sum is σ = 62802255447008. Its totient is φ = 5471885352960.

The previous prime is 21112100111033. The next prime is 21112100111149. The reversal of 21112100111100 is 111100121112.

It is a super-2 number, since 2×21112100111100² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9385764 + ... + 11415636.

Almost surely, 2^{21112100111100} is an apocalyptic number.

21112100111100 is a gapful number since it is divisible by the number (20) 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 21112100111100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31401127723504).

21112100111100 is an abundant number, since it is smaller than the sum of its proper divisors (41690155335908).

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

21112100111100 is a wasteful number, since it uses less digits than its factorization.

21112100111100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2030864 (or 2030857 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21112100111100 its reverse (111100121112), we get a palindrome (21223200232212).

The spelling of 21112100111100 in words is "twenty-one trillion, one hundred twelve billion, one hundred million, one hundred eleven thousand, one hundred".