138215679 has 16 divisors (see below), whose sum is σ = 214589952. Its totient is φ = 77489568.

The previous prime is 138215657. The next prime is 138215681. The reversal of 138215679 is 976512831.

138215679 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138215679 - 2⁵ = 138215647 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138215679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138215699) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60979 + ... + 63204.

It is an arithmetic number, because the mean of its divisors is an integer number (13411872).

Almost surely, 2^138215679 is an apocalyptic number.

138215679 is a deficient number, since it is larger than the sum of its proper divisors (76374273).

138215679 is a wasteful number, since it uses less digits than its factorization.

138215679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124246.

The product of its digits is 90720, while the sum is 42.

The square root of 138215679 is about 11756.5164483362. The cubic root of 138215679 is about 517.0340009090.

The spelling of 138215679 in words is "one hundred thirty-eight million, two hundred fifteen thousand, six hundred seventy-nine".