18806 has 4 divisors (see below), whose sum is σ = 28212. Its totient is φ = 9402.

The previous prime is 18803. The next prime is 18839. The reversal of 18806 is 60881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60881 = 23 ⋅2647.

It is a plaindrome in base 8 and base 15.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4700 + ... + 4703.

It is an arithmetic number, because the mean of its divisors is an integer number (7053).

2¹⁸⁸⁰⁶ is an apocalyptic number.

18806 is a deficient number, since it is larger than the sum of its proper divisors (9406).

18806 is an equidigital number, since it uses as much as digits as its factorization.

18806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9405.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 18806 is about 137.1349700113. The cubic root of 18806 is about 26.5928863334.

The spelling of 18806 in words is "eighteen thousand, eight hundred six".