21552288 has 96 divisors (see below), whose sum is σ = 60673536. Its totient is φ = 6682368.

The previous prime is 21552283. The next prime is 21552317. The reversal of 21552288 is 88225512.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×21552288³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21552283) 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, 94831 + ... + 95057.

It is an arithmetic number, because the mean of its divisors is an integer number (632016).

Almost surely, 2^21552288 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 21552288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30336768).

21552288 is an abundant number, since it is smaller than the sum of its proper divisors (39121248).

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

21552288 is a wasteful number, since it uses less digits than its factorization.

21552288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306 (or 298 counting only the distinct ones).

The product of its digits is 12800, while the sum is 33.

The square root of 21552288 is about 4642.4441838325. Note that the first 3 decimals coincide. The cubic root of 21552288 is about 278.2901237699.

The spelling of 21552288 in words is "twenty-one million, five hundred fifty-two thousand, two hundred eighty-eight".