18012 has 24 divisors (see below), whose sum is σ = 44800. Its totient is φ = 5616.

The previous prime is 17989. The next prime is 18013. The reversal of 18012 is 21081.

It is a happy number.

18012 is nontrivially palindromic in base 8.

It is a super-3 number, since 3×18012³ = 17531015333184, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

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 (18013) by changing a digit.

18012 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189 + ... + 267.

2¹⁸⁰¹² is an apocalyptic number.

18012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22400).

18012 is an abundant number, since it is smaller than the sum of its proper divisors (26788).

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

18012 is a wasteful number, since it uses less digits than its factorization.

18012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 18012 is about 134.2087925585. The cubic root of 18012 is about 26.2132365181.

Adding to 18012 its reverse (21081), we get a palindrome (39093).

The spelling of 18012 in words is "eighteen thousand, twelve".