18397 has 2 divisors, whose sum is σ = 18398.
Its totient is φ = 18396.
The previous prime is 18379. The next prime is 18401. The reversal of 18397 is 79381.
18397 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.
Together with previous prime (18379) it forms an Ormiston pair, because they use the same digits, order apart.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 17956 + 441 = 134^2 + 21^2
It is a cyclic number.
It is not a de Polignac number, because 18397 - 27 = 18269 is a prime.
It is a Chen prime.
18397 is a lucky number.
It is a plaindrome in base 16.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (18307) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9198 + 9199.
It is an arithmetic number, because the mean of its divisors is an integer number (9199).
218397 is an apocalyptic number.
18397 is the 73-rd centered heptagonal number.
It is an amenable number.
18397 is a deficient number, since it is larger than the sum of its proper divisors (1).
18397 is an equidigital number, since it uses as much as digits as its factorization.
18397 is an evil number, because the sum of its binary digits is even.
The product of its digits is 1512, while the sum is 28.
The square root of 18397 is about 135.6355410650.
The cubic root of 18397 is about 26.3986875687.
The spelling of 18397 in words is "eighteen thousand, three hundred ninety-seven".