138638 has 8 divisors (see below), whose sum is σ = 210288. Its totient is φ = 68544.

The previous prime is 138637. The next prime is 138641. The reversal of 138638 is 836831.

138638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 138638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131 + ... + 542.

It is an arithmetic number, because the mean of its divisors is an integer number (26286).

2¹³⁸⁶³⁸ is an apocalyptic number.

138638 is a deficient number, since it is larger than the sum of its proper divisors (71650).

138638 is a wasteful number, since it uses less digits than its factorization.

138638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778.

The product of its digits is 3456, while the sum is 29.

The square root of 138638 is about 372.3412413365. The cubic root of 138638 is about 51.7560068331.

The spelling of 138638 in words is "one hundred thirty-eight thousand, six hundred thirty-eight".