21100113312 has 96 divisors (see below), whose sum is σ = 58974350400. Its totient is φ = 6582571008.

The previous prime is 21100113311. The next prime is 21100113361. The reversal of 21100113312 is 21331100112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 21100113291 and 21100113300.

It is not an unprimeable number, because it can be changed into a prime (21100113311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 256014 + ... + 328242.

It is an arithmetic number, because the mean of its divisors is an integer number (614316150).

Almost surely, 2^21100113312 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 21100113312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29487175200).

21100113312 is an abundant number, since it is smaller than the sum of its proper divisors (37874237088).

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

21100113312 is a wasteful number, since it uses less digits than its factorization.

21100113312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72438 (or 72430 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21100113312 its reverse (21331100112), we get a palindrome (42431213424).

The spelling of 21100113312 in words is "twenty-one billion, one hundred million, one hundred thirteen thousand, three hundred twelve".