138568 has 8 divisors (see below), whose sum is σ = 259830. Its totient is φ = 69280.

The previous prime is 138563. The next prime is 138569. The reversal of 138568 is 865831.

It can be written as a sum of positive squares in only one way, i.e., 128164 + 10404 = 358^2 + 102^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (138563) by changing a digit.

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 as a sum of consecutive naturals, namely, 8653 + ... + 8668.

2¹³⁸⁵⁶⁸ is an apocalyptic number.

It is an amenable number.

138568 is a deficient number, since it is larger than the sum of its proper divisors (121262).

138568 is a wasteful number, since it uses less digits than its factorization.

138568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17327 (or 17323 counting only the distinct ones).

The product of its digits is 5760, while the sum is 31.

The square root of 138568 is about 372.2472296740. The cubic root of 138568 is about 51.7472946224.

The spelling of 138568 in words is "one hundred thirty-eight thousand, five hundred sixty-eight".