18973 has 2 divisors, whose sum is σ = 18974. Its totient is φ = 18972.

The previous prime is 18959. The next prime is 18979. The reversal of 18973 is 37981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15129 + 3844 = 123^2 + 62^2 .

It is a cyclic number.

It is not a de Polignac number, because 18973 - 2⁹ = 18461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18979) 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, 9486 + 9487.

It is an arithmetic number, because the mean of its divisors is an integer number (9487).

2¹⁸⁹⁷³ is an apocalyptic number.

It is an amenable number.

18973 is a deficient number, since it is larger than the sum of its proper divisors (1).

18973 is an equidigital number, since it uses as much as digits as its factorization.

18973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 28.

The square root of 18973 is about 137.7425134082. The cubic root of 18973 is about 26.6713706979.

It can be divided in two parts, 189 and 73, that added together give a palindrome (262).

The spelling of 18973 in words is "eighteen thousand, nine hundred seventy-three".