21224316 has 24 divisors (see below), whose sum is σ = 49619584. Its totient is φ = 7061040.

The previous prime is 21224297. The next prime is 21224321. The reversal of 21224316 is 61342212.

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 = 21224292 and 21224301.

It is a congruent number.

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, 6171 + ... + 8973.

Almost surely, 2^21224316 is an apocalyptic number.

It is an amenable number.

21224316 is an abundant number, since it is smaller than the sum of its proper divisors (28395268).

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

21224316 is a wasteful number, since it uses less digits than its factorization.

21224316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3441 (or 3439 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 21224316 is about 4606.9855654213. The cubic root of 21224316 is about 276.8712752345.

Adding to 21224316 its reverse (61342212), we get a palindrome (82566528).

The spelling of 21224316 in words is "twenty-one million, two hundred twenty-four thousand, three hundred sixteen".