21100112012 has 24 divisors (see below), whose sum is σ = 42375342240. Its totient is φ = 9005379840.

The previous prime is 21100111999. The next prime is 21100112017. The reversal of 21100112012 is 21021100112.

It is a junction number, because it is equal to n+sod(n) for n = 21100111984 and 21100112002.

It is not an unprimeable number, because it can be changed into a prime (21100112017) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1556687 + ... + 1570182.

It is an arithmetic number, because the mean of its divisors is an integer number (1765639260).

Almost surely, 2^21100112012 is an apocalyptic number.

It is an amenable number.

21100112012 is an abundant number, since it is smaller than the sum of its proper divisors (21275230228).

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

21100112012 is a wasteful number, since it uses less digits than its factorization.

21100112012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3127121 (or 3127119 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21100112012 its reverse (21021100112), we get a palindrome (42121212124).

The spelling of 21100112012 in words is "twenty-one billion, one hundred million, one hundred twelve thousand, twelve".