21353224 has 32 divisors (see below), whose sum is σ = 42661080. Its totient is φ = 9985024.

The previous prime is 21353219. The next prime is 21353243. The reversal of 21353224 is 42235312.

It can be written as a sum of positive squares in 4 ways, for example, as 21252100 + 101124 = 4610^2 + 318^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21353195 and 21353204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26394 + ... + 27190.

Almost surely, 2^21353224 is an apocalyptic number.

It is an amenable number.

21353224 is a deficient number, since it is larger than the sum of its proper divisors (21307856).

21353224 is a wasteful number, since it uses less digits than its factorization.

21353224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1017 (or 1013 counting only the distinct ones).

The product of its digits is 1440, while the sum is 22.

The square root of 21353224 is about 4620.9548796758. The cubic root of 21353224 is about 277.4306793274.

Adding to 21353224 its reverse (42235312), we get a palindrome (63588536).

The spelling of 21353224 in words is "twenty-one million, three hundred fifty-three thousand, two hundred twenty-four".