21983872 has 64 divisors (see below), whose sum is σ = 46267200. Its totient is φ = 10393600.

The previous prime is 21983869. The next prime is 21983881. The reversal of 21983872 is 27838912.

21983872 is nontrivially palindromic in base 3.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×21983872² = 966581256224768, which contains 22 as substring.

It is a plaindrome in base 11.

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 7 ways as a sum of consecutive naturals, for example, 309597 + ... + 309667.

It is an arithmetic number, because the mean of its divisors is an integer number (722925).

Almost surely, 2^21983872 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 21983872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23133600).

21983872 is an abundant number, since it is smaller than the sum of its proper divisors (24283328).

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

21983872 is an equidigital number, since it uses as much as digits as its factorization.

21983872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 173 counting only the distinct ones).

The product of its digits is 48384, while the sum is 40.

The square root of 21983872 is about 4688.6961940394. The cubic root of 21983872 is about 280.1354446747.

The spelling of 21983872 in words is "twenty-one million, nine hundred eighty-three thousand, eight hundred seventy-two".