138505679 has 8 divisors (see below), whose sum is σ = 149718240. Its totient is φ = 127372896.

The previous prime is 138505657. The next prime is 138505691. The reversal of 138505679 is 976505831.

138505679 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 cyclic number.

It is not a de Polignac number, because 138505679 - 2²⁴ = 121728463 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 (138505979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16307 + ... + 23300.

It is an arithmetic number, because the mean of its divisors is an integer number (18714780).

Almost surely, 2^138505679 is an apocalyptic number.

138505679 is a deficient number, since it is larger than the sum of its proper divisors (11212561).

138505679 is a wasteful number, since it uses less digits than its factorization.

138505679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39889.

The product of its (nonzero) digits is 226800, while the sum is 44.

The square root of 138505679 is about 11768.8435710566. The cubic root of 138505679 is about 517.3953567189.

The spelling of 138505679 in words is "one hundred thirty-eight million, five hundred five thousand, six hundred seventy-nine".