21888768 has 72 divisors (see below), whose sum is σ = 63576576. Its totient is φ = 6630400.

The previous prime is 21888751. The next prime is 21888787. The reversal of 21888768 is 86788812.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7153 + ... + 9743.

It is an arithmetic number, because the mean of its divisors is an integer number (883008).

Almost surely, 2^21888768 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 21888768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31788288).

21888768 is an abundant number, since it is smaller than the sum of its proper divisors (41687808).

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

21888768 is a wasteful number, since it uses less digits than its factorization.

21888768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2621 (or 2607 counting only the distinct ones).

The product of its digits is 344064, while the sum is 48.

The square root of 21888768 is about 4678.5433630565. The cubic root of 21888768 is about 279.7308979171.

The spelling of 21888768 in words is "twenty-one million, eight hundred eighty-eight thousand, seven hundred sixty-eight".