21448 has 16 divisors (see below), whose sum is σ = 46080. Its totient is φ = 9168.

The previous prime is 21433. The next prime is 21467. The reversal of 21448 is 84412.

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 13.

It is a zygodrome in base 13.

It is a congruent number.

It is an unprimeable number.

21448 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136 + ... + 247.

It is an arithmetic number, because the mean of its divisors is an integer number (2880).

2²¹⁴⁴⁸ is an apocalyptic number.

21448 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21448 is an abundant number, since it is smaller than the sum of its proper divisors (24632).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23040).

21448 is a wasteful number, since it uses less digits than its factorization.

21448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 392 counting only the distinct ones).

The product of its digits is 256, while the sum is 19.

The square root of 21448 is about 146.4513571122. The cubic root of 21448 is about 27.7840531007.

It can be divided in two parts, 214 and 48, that added together give a palindrome (262).

The spelling of 21448 in words is "twenty-one thousand, four hundred forty-eight".