21123323112 has 64 divisors (see below), whose sum is σ = 55687104000. Its totient is φ = 6658593984.

The previous prime is 21123323077. The next prime is 21123323153. The reversal of 21123323112 is 21132332112.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 215589 + ... + 297867.

It is an arithmetic number, because the mean of its divisors is an integer number (870111000).

Almost surely, 2^21123323112 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 21123323112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27843552000).

21123323112 is an abundant number, since it is smaller than the sum of its proper divisors (34563780888).

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

21123323112 is a wasteful number, since it uses less digits than its factorization.

21123323112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82870 (or 82866 counting only the distinct ones).

The product of its digits is 432, while the sum is 21.

Adding to 21123323112 its reverse (21132332112), we get a palindrome (42255655224).

The spelling of 21123323112 in words is "twenty-one billion, one hundred twenty-three million, three hundred twenty-three thousand, one hundred twelve".