21111101102100 has 144 divisors (see below), whose sum is σ = 61760712686400. Its totient is φ = 5567207377920.

The previous prime is 21111101102093. The next prime is 21111101102197. The reversal of 21111101102100 is 120110111112.

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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17686986 + ... + 18842814.

It is an arithmetic number, because the mean of its divisors is an integer number (428893838100).

Almost surely, 2^{21111101102100} is an apocalyptic number.

21111101102100 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 21111101102100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30880356343200).

21111101102100 is an abundant number, since it is smaller than the sum of its proper divisors (40649611584300).

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

21111101102100 is a wasteful number, since it uses less digits than its factorization.

21111101102100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1156522 (or 1156515 counting only the distinct ones).

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

Adding to 21111101102100 its reverse (120110111112), we get a palindrome (21231211213212).

The spelling of 21111101102100 in words is "twenty-one trillion, one hundred eleven billion, one hundred one million, one hundred two thousand, one hundred".