21383552 has 64 divisors (see below), whose sum is σ = 46707840. Its totient is φ = 9707520.

The previous prime is 21383503. The next prime is 21383573. The reversal of 21383552 is 25538312.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×21383552³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67298 + ... + 67614.

It is an arithmetic number, because the mean of its divisors is an integer number (729810).

Almost surely, 2^21383552 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 21383552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23353920).

21383552 is an abundant number, since it is smaller than the sum of its proper divisors (25324288).

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

21383552 is a wasteful number, since it uses less digits than its factorization.

21383552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379 (or 367 counting only the distinct ones).

The product of its digits is 7200, while the sum is 29.

The square root of 21383552 is about 4624.2352881314. The cubic root of 21383552 is about 277.5619621937.

The spelling of 21383552 in words is "twenty-one million, three hundred eighty-three thousand, five hundred fifty-two".