21315112 has 128 divisors (see below), whose sum is σ = 54835200. Its totient is φ = 7527168.

The previous prime is 21315109. The next prime is 21315137. The reversal of 21315112 is 21151312.

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 31 ways as a sum of consecutive naturals, for example, 318103 + ... + 318169.

It is an arithmetic number, because the mean of its divisors is an integer number (428400).

Almost surely, 2^21315112 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 21315112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27417600).

21315112 is an abundant number, since it is smaller than the sum of its proper divisors (33520088).

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

21315112 is a wasteful number, since it uses less digits than its factorization.

21315112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 131 counting only the distinct ones).

The product of its digits is 60, while the sum is 16.

The square root of 21315112 is about 4616.8292149483. The cubic root of 21315112 is about 277.2655249552.

Adding to 21315112 its reverse (21151312), we get a palindrome (42466424).

The spelling of 21315112 in words is "twenty-one million, three hundred fifteen thousand, one hundred twelve".