18845 has 4 divisors (see below), whose sum is σ = 22620. Its totient is φ = 15072.

The previous prime is 18839. The next prime is 18859. The reversal of 18845 is 54881.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11449 + 7396 = 107^2 + 86^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18845 is a prime.

It is a Curzon number.

It is a plaindrome in base 16.

It is a nialpdrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1880 + ... + 1889.

It is an arithmetic number, because the mean of its divisors is an integer number (5655).

2¹⁸⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

18845 is a deficient number, since it is larger than the sum of its proper divisors (3775).

18845 is an equidigital number, since it uses as much as digits as its factorization.

18845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3774.

The product of its digits is 1280, while the sum is 26.

The square root of 18845 is about 137.2770920438. The cubic root of 18845 is about 26.6112564717.

The spelling of 18845 in words is "eighteen thousand, eight hundred forty-five".