21000023112 has 32 divisors (see below), whose sum is σ = 54310406400. Its totient is φ = 6758627904.

The previous prime is 21000023111. The next prime is 21000023119. The reversal of 21000023112 is 21132000012.

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

It is not an unprimeable number, because it can be changed into a prime (21000023111) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15085528 + ... + 15086919.

It is an arithmetic number, because the mean of its divisors is an integer number (1697200200).

Almost surely, 2^21000023112 is an apocalyptic number.

It is an amenable number.

21000023112 is an abundant number, since it is smaller than the sum of its proper divisors (33310383288).

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

21000023112 is a wasteful number, since it uses less digits than its factorization.

21000023112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30172485 (or 30172481 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21000023112 its reverse (21132000012), we get a palindrome (42132023124).

The spelling of 21000023112 in words is "twenty-one billion, twenty-three thousand, one hundred twelve".