21303888 has 60 divisors (see below), whose sum is σ = 57600480. Its totient is φ = 6784448.

The previous prime is 21303857. The next prime is 21303901. The reversal of 21303888 is 88830312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24973 + ... + 25811.

It is an arithmetic number, because the mean of its divisors is an integer number (960008).

Almost surely, 2^21303888 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 21303888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28800240).

21303888 is an abundant number, since it is smaller than the sum of its proper divisors (36296592).

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

21303888 is a wasteful number, since it uses less digits than its factorization.

21303888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 896 (or 867 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 21303888 is about 4615.6135020168. The cubic root of 21303888 is about 277.2168494013.

The spelling of 21303888 in words is "twenty-one million, three hundred three thousand, eight hundred eighty-eight".