21222324 has 60 divisors (see below), whose sum is σ = 58758084. Its totient is φ = 6656256.

The previous prime is 21222293. The next prime is 21222343. The reversal of 21222324 is 42322212.

It can be written as a sum of positive squares in 2 ways, for example, as 19448100 + 1774224 = 4410^2 + 1332^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is a junction number, because it is equal to n+sod(n) for n = 21222297 and 21222306.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3582 + ... + 7434.

Almost surely, 2^21222324 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 21222324, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29379042).

21222324 is an abundant number, since it is smaller than the sum of its proper divisors (37535760).

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

21222324 is a wasteful number, since it uses less digits than its factorization.

21222324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3886 (or 3875 counting only the distinct ones).

The product of its digits is 384, while the sum is 18.

The square root of 21222324 is about 4606.7693669208. The cubic root of 21222324 is about 276.8626130812.

Adding to 21222324 its reverse (42322212), we get a palindrome (63544536).

The spelling of 21222324 in words is "twenty-one million, two hundred twenty-two thousand, three hundred twenty-four".