138191709 has 8 divisors (see below), whose sum is σ = 184788000. Its totient is φ = 91861616.

The previous prime is 138191687. The next prime is 138191717. The reversal of 138191709 is 907191831.

138191709 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 138191709 - 2¹⁵ = 138158941 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138191719) 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, 65334 + ... + 67415.

It is an arithmetic number, because the mean of its divisors is an integer number (23098500).

Almost surely, 2^138191709 is an apocalyptic number.

It is an amenable number.

138191709 is a deficient number, since it is larger than the sum of its proper divisors (46596291).

138191709 is a wasteful number, since it uses less digits than its factorization.

138191709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133099.

The product of its (nonzero) digits is 13608, while the sum is 39.

The square root of 138191709 is about 11755.4969695032. The cubic root of 138191709 is about 517.0041103747.

The spelling of 138191709 in words is "one hundred thirty-eight million, one hundred ninety-one thousand, seven hundred nine".