18943 has 4 divisors (see below), whose sum is σ = 19960. Its totient is φ = 17928.
The previous prime is 18919. The next prime is 18947. The reversal of 18943 is 34981.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is not a de Polignac number, because 18943 - 25 = 18911 is a prime.
It is an Ulam number.
It is an alternating number because its digits alternate between odd and even.
It is a Duffinian number.
18943 is a lucky number.
It is a plaindrome in base 8 and base 16.
It is a zygodrome in base 8.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (18947) 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 3 ways as a sum of consecutive naturals, for example, 480 + ... + 517.
It is an arithmetic number, because the mean of its divisors is an integer number (4990).
218943 is an apocalyptic number.
18943 is a deficient number, since it is larger than the sum of its proper divisors (1017).
18943 is an equidigital number, since it uses as much as digits as its factorization.
18943 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1016.
The product of its digits is 864, while the sum is 25.
The square root of 18943 is about 137.6335714860. The cubic root of 18943 is about 26.6573057422.
It can be divided in two parts, 189 and 43, that added together give a palindrome (232).
The spelling of 18943 in words is "eighteen thousand, nine hundred forty-three".
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