21384768 has 56 divisors (see below), whose sum is σ = 57091072. Its totient is φ = 7064064.

The previous prime is 21384767. The next prime is 21384773. The reversal of 21384768 is 86748312.

It is not an unprimeable number, because it can be changed into a prime (21384763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23946 + ... + 24822.

Almost surely, 2^21384768 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 21384768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28545536).

21384768 is an abundant number, since it is smaller than the sum of its proper divisors (35706304).

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

21384768 is a wasteful number, since it uses less digits than its factorization.

21384768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1019 (or 1009 counting only the distinct ones).

The product of its digits is 64512, while the sum is 39.

The square root of 21384768 is about 4624.3667674612. The cubic root of 21384768 is about 277.5672233862.

The spelling of 21384768 in words is "twenty-one million, three hundred eighty-four thousand, seven hundred sixty-eight".