19668 has 24 divisors (see below), whose sum is σ = 50400. Its totient is φ = 5920.

The previous prime is 19661. The next prime is 19681. The reversal of 19668 is 86691.

It is a plaindrome in base 7.

It is a nialpdrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19661) by changing a digit.

19668 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 7 ways as a sum of consecutive naturals, for example, 58 + ... + 206.

It is an arithmetic number, because the mean of its divisors is an integer number (2100).

2¹⁹⁶⁶⁸ 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 19668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25200).

19668 is an abundant number, since it is smaller than the sum of its proper divisors (30732).

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

19668 is a wasteful number, since it uses less digits than its factorization.

19668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 165 counting only the distinct ones).

The product of its digits is 2592, while the sum is 30.

The square root of 19668 is about 140.2426468661. The cubic root of 19668 is about 26.9931395464.

It can be divided in two parts, 1 and 9668, that added together give a palindrome (9669).

The spelling of 19668 in words is "nineteen thousand, six hundred sixty-eight".