21113224 has 32 divisors (see below), whose sum is σ = 43747200. Its totient is φ = 9472320.

The previous prime is 21113221. The next prime is 21113231. The reversal of 21113224 is 42231112.

It is a junction number, because it is equal to n+sod(n) for n = 21113198 and 21113207.

It is not an unprimeable number, because it can be changed into a prime (21113221) 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, 5434 + ... + 8470.

It is an arithmetic number, because the mean of its divisors is an integer number (1367100).

Almost surely, 2^21113224 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 21113224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21873600).

21113224 is an abundant number, since it is smaller than the sum of its proper divisors (22633976).

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

21113224 is a wasteful number, since it uses less digits than its factorization.

21113224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3133 (or 3129 counting only the distinct ones).

The product of its digits is 96, while the sum is 16.

The square root of 21113224 is about 4594.9128392169. The cubic root of 21113224 is about 276.3873647835.

Adding to 21113224 its reverse (42231112), we get a palindrome (63344336).

It can be divided in two parts, 2111 and 3224, that added together give a palindrome (5335).

The spelling of 21113224 in words is "twenty-one million, one hundred thirteen thousand, two hundred twenty-four".