21231112 has 48 divisors (see below), whose sum is σ = 47473020. Its totient is φ = 8870400.

The previous prime is 21231107. The next prime is 21231143. The reversal of 21231112 is 21113212.

It can be written as a sum of positive squares in 2 ways, for example, as 21215236 + 15876 = 4606^2 + 126^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21231092 and 21231101.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15412 + ... + 16732.

Almost surely, 2^21231112 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 21231112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23736510).

21231112 is an abundant number, since it is smaller than the sum of its proper divisors (26241908).

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

21231112 is a wasteful number, since it uses less digits than its factorization.

21231112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1382 (or 1371 counting only the distinct ones).

The product of its digits is 24, while the sum is 13.

The square root of 21231112 is about 4607.7230819571. The cubic root of 21231112 is about 276.9008233621.

Adding to 21231112 its reverse (21113212), we get a palindrome (42344324).

The spelling of 21231112 in words is "twenty-one million, two hundred thirty-one thousand, one hundred twelve".