21333936 has 80 divisors (see below), whose sum is σ = 59996160. Its totient is φ = 6493440.

The previous prime is 21333919. The next prime is 21333947. The reversal of 21333936 is 63933312.

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, 111601 + ... + 111791.

It is an arithmetic number, because the mean of its divisors is an integer number (749952).

Almost surely, 2^21333936 is an apocalyptic number.

21333936 is a gapful number since it is divisible by the number (26) 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 21333936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29998080).

21333936 is an abundant number, since it is smaller than the sum of its proper divisors (38662224).

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

21333936 is a wasteful number, since it uses less digits than its factorization.

21333936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394 (or 388 counting only the distinct ones).

The product of its digits is 8748, while the sum is 30.

The square root of 21333936 is about 4618.8673936367. The cubic root of 21333936 is about 277.3471213765.

The spelling of 21333936 in words is "twenty-one million, three hundred thirty-three thousand, nine hundred thirty-six".