21748032 has 84 divisors (see below), whose sum is σ = 66033396. Its totient is φ = 6819840.

The previous prime is 21748009. The next prime is 21748033. The reversal of 21748032 is 23084712.

It can be written as a sum of positive squares in 2 ways, for example, as 15872256 + 5875776 = 3984^2 + 2424^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21747987 and 21748005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21748033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8682 + ... + 10902.

Almost surely, 2^21748032 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 21748032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33016698).

21748032 is an abundant number, since it is smaller than the sum of its proper divisors (44285364).

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

21748032 is a wasteful number, since it uses less digits than its factorization.

21748032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2256 (or 2243 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21748032 is about 4663.4785300246. The cubic root of 21748032 is about 279.1300892549.

The spelling of 21748032 in words is "twenty-one million, seven hundred forty-eight thousand, thirty-two".