21744752 has 40 divisors (see below), whose sum is σ = 45178656. Its totient is φ = 10112256.

The previous prime is 21744739. The next prime is 21744757. The reversal of 21744752 is 25744712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21744757) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12818 + ... + 14414.

Almost surely, 2^21744752 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 21744752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22589328).

21744752 is an abundant number, since it is smaller than the sum of its proper divisors (23433904).

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

21744752 is a wasteful number, since it uses less digits than its factorization.

21744752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665 (or 1659 counting only the distinct ones).

The product of its digits is 15680, while the sum is 32.

The square root of 21744752 is about 4663.1268479423. The cubic root of 21744752 is about 279.1160559127.

The spelling of 21744752 in words is "twenty-one million, seven hundred forty-four thousand, seven hundred fifty-two".