21100113012 has 96 divisors (see below), whose sum is σ = 55339208064. Its totient is φ = 6202828800.

The previous prime is 21100112993. The next prime is 21100113049. The reversal of 21100113012 is 21031100112.

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 (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 569848 + ... + 605744.

It is an arithmetic number, because the mean of its divisors is an integer number (576450084).

Almost surely, 2^21100113012 is an apocalyptic number.

21100113012 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 21100113012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27669604032).

21100113012 is an abundant number, since it is smaller than the sum of its proper divisors (34239095052).

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

21100113012 is a wasteful number, since it uses less digits than its factorization.

21100113012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36049 (or 36047 counting only the distinct ones).

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

Adding to 21100113012 its reverse (21031100112), we get a palindrome (42131213124).

The spelling of 21100113012 in words is "twenty-one billion, one hundred million, one hundred thirteen thousand, twelve".