138128 has 20 divisors (see below), whose sum is σ = 273420. Its totient is φ = 67584.

The previous prime is 138113. The next prime is 138139. The reversal of 138128 is 821831.

It can be written as a sum of positive squares in 2 ways, for example, as 43264 + 94864 = 208^2 + 308^2 .

It is an unprimeable 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 3 ways as a sum of consecutive naturals, for example, 1376 + ... + 1472.

It is an arithmetic number, because the mean of its divisors is an integer number (13671).

2¹³⁸¹²⁸ is an apocalyptic number.

It is an amenable number.

138128 is a deficient number, since it is larger than the sum of its proper divisors (135292).

138128 is an equidigital number, since it uses as much as digits as its factorization.

138128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194 (or 188 counting only the distinct ones).

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

The square root of 138128 is about 371.6557546978. The cubic root of 138128 is about 51.6924648594.

Adding to 138128 its reverse (821831), we get a palindrome (959959).

The spelling of 138128 in words is "one hundred thirty-eight thousand, one hundred twenty-eight".