123138 has 12 divisors (see below), whose sum is σ = 266838. Its totient is φ = 41040.

The previous prime is 123127. The next prime is 123143. The reversal of 123138 is 831321.

It can be written as a sum of positive squares in only one way, i.e., 91809 + 31329 = 303^2 + 177^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 6841 = 123138 / (1 + 2 + 3 + 1 + 3 + 8).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 123138.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3403 + ... + 3438.

2¹²³¹³⁸ is an apocalyptic number.

123138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

123138 is an abundant number, since it is smaller than the sum of its proper divisors (143700).

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

123138 is a wasteful number, since it uses less digits than its factorization.

123138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6849 (or 6846 counting only the distinct ones).

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

The square root of 123138 is about 350.9102449345. The cubic root of 123138 is about 49.7504903027.

Adding to 123138 its reverse (831321), we get a palindrome (954459).

It can be divided in two parts, 12313 and 8, that added together give a palindrome (12321).

The spelling of 123138 in words is "one hundred twenty-three thousand, one hundred thirty-eight".