18997 has 6 divisors (see below), whose sum is σ = 21014. Its totient is φ = 17160.

The previous prime is 18979. The next prime is 19001. The reversal of 18997 is 79981.

It can be written as a sum of positive squares in only one way, i.e., 14641 + 4356 = 121^2 + 66^2 .

It is not a de Polignac number, because 18997 - 2⁷ = 18869 is a prime.

It is a Duffinian number.

Its product of digits (4536) is a multiple of the sum of its prime divisors (168).

It is a plaindrome in base 14.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18917) 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 in 5 ways as a sum of consecutive naturals, for example, 43 + ... + 199.

2¹⁸⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

18997 is a deficient number, since it is larger than the sum of its proper divisors (2017).

18997 is a wasteful number, since it uses less digits than its factorization.

18997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 168 counting only the distinct ones).

The product of its digits is 4536, while the sum is 34.

The square root of 18997 is about 137.8296049476. The cubic root of 18997 is about 26.6826119914.

It can be divided in two parts, 1 and 8997, that added together give a palindrome (8998).

The spelling of 18997 in words is "eighteen thousand, nine hundred ninety-seven".