21360768 has 128 divisors (see below), whose sum is σ = 66830400. Its totient is φ = 5959680.

The previous prime is 21360761. The next prime is 21360799. The reversal of 21360768 is 86706312.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21360761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54718 + ... + 55106.

Almost surely, 2^21360768 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 21360768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33415200).

21360768 is an abundant number, since it is smaller than the sum of its proper divisors (45469632).

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

21360768 is a wasteful number, since it uses less digits than its factorization.

21360768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 21360768 is about 4621.7710890956. The cubic root of 21360768 is about 277.4633471597.

The spelling of 21360768 in words is "twenty-one million, three hundred sixty thousand, seven hundred sixty-eight".