21824416 has 24 divisors (see below), whose sum is σ = 43367940. Its totient is φ = 10810368.

The previous prime is 21824381. The next prime is 21824417. The reversal of 21824416 is 61442812.

It can be written as a sum of positive squares in 2 ways, for example, as 17808400 + 4016016 = 4220^2 + 2004^2 .

It is not an unprimeable number, because it can be changed into a prime (21824417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360 + ... + 6616.

Almost surely, 2^21824416 is an apocalyptic number.

It is an amenable number.

21824416 is a deficient number, since it is larger than the sum of its proper divisors (21543524).

21824416 is a wasteful number, since it uses less digits than its factorization.

21824416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6376 (or 6368 counting only the distinct ones).

The product of its digits is 3072, while the sum is 28.

The square root of 21824416 is about 4671.6609466013. The cubic root of 21824416 is about 279.4564967179.

The spelling of 21824416 in words is "twenty-one million, eight hundred twenty-four thousand, four hundred sixteen".