18859 has 2 divisors, whose sum is σ = 18860.
Its totient is φ = 18858.
The previous prime is 18839. The next prime is 18869. The reversal of 18859 is 95881.
It is a strong prime.
It is an emirp because it is prime and its reverse (95881) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 18859 - 27 = 18731 is a prime.
It is a Chen prime.
It is a plaindrome in base 16.
It is a self number, because there is not a number n which added to its sum of digits gives 18859.
It is not a weakly prime, because it can be changed into another prime (18839) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9429 + 9430.
It is an arithmetic number, because the mean of its divisors is an integer number (9430).
218859 is an apocalyptic number.
18859 is a deficient number, since it is larger than the sum of its proper divisors (1).
18859 is an equidigital number, since it uses as much as digits as its factorization.
18859 is an evil number, because the sum of its binary digits is even.
The product of its digits is 2880, while the sum is 31.
The square root of 18859 is about 137.3280743330.
The cubic root of 18859 is about 26.6178446979.
The spelling of 18859 in words is "eighteen thousand, eight hundred fifty-nine".