21968352 has 144 divisors (see below), whose sum is σ = 75714912. Its totient is φ = 5898240.

The previous prime is 21968347. The next prime is 21968363. The reversal of 21968352 is 25386912.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 23 ways as a sum of consecutive naturals, for example, 33952 + ... + 34592.

It is an arithmetic number, because the mean of its divisors is an integer number (525798).

Almost surely, 2^21968352 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 21968352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37857456).

21968352 is an abundant number, since it is smaller than the sum of its proper divisors (53746560).

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

21968352 is a wasteful number, since it uses less digits than its factorization.

21968352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681 (or 670 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21968352 is about 4687.0408575134. The cubic root of 21968352 is about 280.0695065539.

The spelling of 21968352 in words is "twenty-one million, nine hundred sixty-eight thousand, three hundred fifty-two".