18306 has 20 divisors (see below), whose sum is σ = 41382. Its totient is φ = 6048.

The previous prime is 18301. The next prime is 18307. The reversal of 18306 is 60381.

18306 is an esthetic number in base 15, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in only one way, i.e., 18225 + 81 = 135^2 + 9^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

18306 is an undulating number in base 15.

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 (18301) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 106 + ... + 218.

2¹⁸³⁰⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18306, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20691).

18306 is an abundant number, since it is smaller than the sum of its proper divisors (23076).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18306 is a wasteful number, since it uses less digits than its factorization.

18306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 18306 is about 135.2996674054. The cubic root of 18306 is about 26.3550889309.

Adding to 18306 its reverse (60381), we get a palindrome (78687).

It can be divided in two parts, 18 and 306, that added together give a square (324 = 18²).

The spelling of 18306 in words is "eighteen thousand, three hundred six".