21283824 has 20 divisors (see below), whose sum is σ = 54983336. Its totient is φ = 7094592.

The previous prime is 21283777. The next prime is 21283841. The reversal of 21283824 is 42838212.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

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 = 21283791 and 21283800.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221659 + ... + 221754.

Almost surely, 2^21283824 is an apocalyptic number.

21283824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21283824 is an abundant number, since it is smaller than the sum of its proper divisors (33699512).

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

21283824 is a wasteful number, since it uses less digits than its factorization.

21283824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443424 (or 443418 counting only the distinct ones).

The product of its digits is 6144, while the sum is 30.

The square root of 21283824 is about 4613.4394978151. The cubic root of 21283824 is about 277.1297944640.

The spelling of 21283824 in words is "twenty-one million, two hundred eighty-three thousand, eight hundred twenty-four".