21333984 has 96 divisors (see below), whose sum is σ = 65318400. Its totient is φ = 5970432.

The previous prime is 21333973. The next prime is 21334007. The reversal of 21333984 is 48933312.

21333984 = T₂₇ + T₂₈ + ... + T₅₀₃.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

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 15 ways as a sum of consecutive naturals, for example, 35317 + ... + 35915.

It is an arithmetic number, because the mean of its divisors is an integer number (680400).

Almost surely, 2^21333984 is an apocalyptic number.

21333984 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 21333984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32659200).

21333984 is an abundant number, since it is smaller than the sum of its proper divisors (43984416).

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

21333984 is a wasteful number, since it uses less digits than its factorization.

21333984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672 (or 664 counting only the distinct ones).

The product of its digits is 15552, while the sum is 33.

The square root of 21333984 is about 4618.8725897128. The cubic root of 21333984 is about 277.3473293808.

The spelling of 21333984 in words is "twenty-one million, three hundred thirty-three thousand, nine hundred eighty-four".