138715439 has 4 divisors (see below), whose sum is σ = 143498760. Its totient is φ = 133932120.

The previous prime is 138715433. The next prime is 138715441. The reversal of 138715439 is 934517831.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138715439 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138715396 and 138715405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138715433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2391617 + ... + 2391674.

It is an arithmetic number, because the mean of its divisors is an integer number (35874690).

Almost surely, 2^138715439 is an apocalyptic number.

138715439 is a deficient number, since it is larger than the sum of its proper divisors (4783321).

138715439 is an equidigital number, since it uses as much as digits as its factorization.

138715439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4783320.

The product of its digits is 90720, while the sum is 41.

The square root of 138715439 is about 11777.7518652755. The cubic root of 138715439 is about 517.6564148687.

The spelling of 138715439 in words is "one hundred thirty-eight million, seven hundred fifteen thousand, four hundred thirty-nine".