138028 has 12 divisors (see below), whose sum is σ = 263592. Its totient is φ = 62720.

The previous prime is 138007. The next prime is 138041. The reversal of 138028 is 820831.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

138028 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1525 + ... + 1612.

It is an arithmetic number, because the mean of its divisors is an integer number (21966).

2¹³⁸⁰²⁸ is an apocalyptic number.

It is an amenable number.

138028 is a deficient number, since it is larger than the sum of its proper divisors (125564).

138028 is a wasteful number, since it uses less digits than its factorization.

138028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3152 (or 3150 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 138028 is about 371.5211972418. The cubic root of 138028 is about 51.6799873158.

Adding to 138028 its reverse (820831), we get a palindrome (958859).

The spelling of 138028 in words is "one hundred thirty-eight thousand, twenty-eight".