18493 has 2 divisors, whose sum is σ = 18494. Its totient is φ = 18492.

The previous prime is 18481. The next prime is 18503. The reversal of 18493 is 39481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15129 + 3364 = 123^2 + 58^2 .

It is a cyclic number.

It is not a de Polignac number, because 18493 - 2⁵ = 18461 is a prime.

18493 is a lucky number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18413) 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, 9246 + 9247.

It is an arithmetic number, because the mean of its divisors is an integer number (9247).

2¹⁸⁴⁹³ is an apocalyptic number.

It is an amenable number.

18493 is a deficient number, since it is larger than the sum of its proper divisors (1).

18493 is an equidigital number, since it uses as much as digits as its factorization.

18493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 18493 is about 135.9889701410. The cubic root of 18493 is about 26.4445261762. Note that the first 3 decimals are identical.

The spelling of 18493 in words is "eighteen thousand, four hundred ninety-three".