12138 has 24 divisors (see below), whose sum is σ = 29472. Its totient is φ = 3264.

The previous prime is 12119. The next prime is 12143. The reversal of 12138 is 83121.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 706 + ... + 722.

It is an arithmetic number, because the mean of its divisors is an integer number (1228).

2¹²¹³⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14736).

12138 is an abundant number, since it is smaller than the sum of its proper divisors (17334).

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

12138 is a wasteful number, since it uses less digits than its factorization.

12138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46 (or 29 counting only the distinct ones).

The product of its digits is 48, while the sum is 15.

The square root of 12138 is about 110.1725918729. The cubic root of 12138 is about 22.9817119905.

Subtracting from 12138 its product of digits (48), we obtain a triangular number (12090 = T₁₅₅).

Adding to 12138 its reverse (83121), we get a palindrome (95259).

It can be divided in two parts, 1213 and 8, that added together give a palindrome (1221).

The spelling of 12138 in words is "twelve thousand, one hundred thirty-eight".