18913 has 2 divisors, whose sum is σ = 18914. Its totient is φ = 18912.

The previous prime is 18911. The next prime is 18917. The reversal of 18913 is 31981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18769 + 144 = 137^2 + 12^2 .

It is an emirp because it is prime and its reverse (31981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18913 - 2¹ = 18911 is a prime.

Together with 18911, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18911) by changing a digit.

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 as a sum of consecutive naturals, namely, 9456 + 9457.

It is an arithmetic number, because the mean of its divisors is an integer number (9457).

2¹⁸⁹¹³ is an apocalyptic number.

It is an amenable number.

18913 is a deficient number, since it is larger than the sum of its proper divisors (1).

18913 is an equidigital number, since it uses as much as digits as its factorization.

18913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 22.

The square root of 18913 is about 137.5245432641. The cubic root of 18913 is about 26.6432259288.

It can be divided in two parts, 189 and 13, that added together give a palindrome (202).

The spelling of 18913 in words is "eighteen thousand, nine hundred thirteen".