138682639 has 4 divisors (see below), whose sum is σ = 138807256. Its totient is φ = 138558024.

The previous prime is 138682637. The next prime is 138682657. The reversal of 138682639 is 936286831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138682639 - 2¹ = 138682637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138682637) 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, 60624 + ... + 62869.

It is an arithmetic number, because the mean of its divisors is an integer number (34701814).

Almost surely, 2^138682639 is an apocalyptic number.

138682639 is a deficient number, since it is larger than the sum of its proper divisors (124617).

138682639 is a wasteful number, since it uses less digits than its factorization.

138682639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124616.

The product of its digits is 373248, while the sum is 46.

The square root of 138682639 is about 11776.3593270586. The cubic root of 138682639 is about 517.6156107857.

The spelling of 138682639 in words is "one hundred thirty-eight million, six hundred eighty-two thousand, six hundred thirty-nine".