21948 has 24 divisors (see below), whose sum is σ = 53760. Its totient is φ = 6960.

The previous prime is 21943. The next prime is 21961. The reversal of 21948 is 84912.

It is a plaindrome in base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 21948.

It is not an unprimeable number, because it can be changed into a prime (21943) by changing a digit.

21948 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 343 + ... + 401.

It is an arithmetic number, because the mean of its divisors is an integer number (2240).

2²¹⁹⁴⁸ is an apocalyptic number.

It is an amenable number.

21948 is an abundant number, since it is smaller than the sum of its proper divisors (31812).

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 (26880).

21948 is a wasteful number, since it uses less digits than its factorization.

21948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 95 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 21948 is about 148.1485740735. The cubic root of 21948 is about 27.9982992164.

It can be divided in two parts, 21 and 948, that added together give a palindrome (969).

The spelling of 21948 in words is "twenty-one thousand, nine hundred forty-eight".