21033984 has 88 divisors (see below), whose sum is σ = 57774528. Its totient is φ = 6799360.

The previous prime is 21033979. The next prime is 21033989. The reversal of 21033984 is 48933012.

It is an interprime number because it is at equal distance from previous prime (21033979) and next prime (21033989).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125869 + ... + 126035.

Almost surely, 2^21033984 is an apocalyptic number.

21033984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21033984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28887264).

21033984 is an abundant number, since it is smaller than the sum of its proper divisors (36740544).

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

21033984 is a wasteful number, since it uses less digits than its factorization.

21033984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 21033984 is about 4586.2821544253. The cubic root of 21033984 is about 276.0411616829.

Adding to 21033984 its reverse (48933012), we get a palindrome (69966996).

The spelling of 21033984 in words is "twenty-one million, thirty-three thousand, nine hundred eighty-four".