21748000 has 48 divisors (see below), whose sum is σ = 53444664. Its totient is φ = 8697600.

The previous prime is 21747997. The next prime is 21748009. The reversal of 21748000 is 84712.

It can be written as a sum of positive squares in 4 ways, for example, as 7033104 + 14714896 = 2652^2 + 3836^2 .

It is not an unprimeable number, because it can be changed into a prime (21748009) 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 7 ways as a sum of consecutive naturals, for example, 1282 + ... + 6718.

Almost surely, 2^21748000 is an apocalyptic number.

21748000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21748000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26722332).

21748000 is an abundant number, since it is smaller than the sum of its proper divisors (31696664).

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

21748000 is an equidigital number, since it uses as much as digits as its factorization.

21748000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5462 (or 5444 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 21748000 is about 4663.4750991080. The cubic root of 21748000 is about 279.1299523510.

The spelling of 21748000 in words is "twenty-one million, seven hundred forty-eight thousand".