21011111120100 has 144 divisors (see below), whose sum is σ = 61747679006720. Its totient is φ = 5515324214400.

The previous prime is 21011111120071. The next prime is 21011111120113. The reversal of 21011111120100 is 102111111012.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6505509 + ... + 9183891.

Almost surely, 2^{21011111120100} is an apocalyptic number.

21011111120100 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 21011111120100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30873839503360).

21011111120100 is an abundant number, since it is smaller than the sum of its proper divisors (40736567886620).

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

21011111120100 is a wasteful number, since it uses less digits than its factorization.

21011111120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2678810 (or 2678803 counting only the distinct ones).

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

Adding to 21011111120100 its reverse (102111111012), we get a palindrome (21113222231112).

It can be divided in two parts, 21011 and 111120100, that added together give a palindrome (111141111).

The spelling of 21011111120100 in words is "twenty-one trillion, eleven billion, one hundred eleven million, one hundred twenty thousand, one hundred".