138108109 has 2 divisors, whose sum is σ = 138108110. Its totient is φ = 138108108.

The previous prime is 138108079. The next prime is 138108133. The reversal of 138108109 is 901801831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 101566084 + 36542025 = 10078^2 + 6045^2 .

It is a cyclic number.

It is not a de Polignac number, because 138108109 - 2⁹ = 138107597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138108199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69054054 + 69054055.

It is an arithmetic number, because the mean of its divisors is an integer number (69054055).

Almost surely, 2^138108109 is an apocalyptic number.

It is an amenable number.

138108109 is a deficient number, since it is larger than the sum of its proper divisors (1).

138108109 is an equidigital number, since it uses as much as digits as its factorization.

138108109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 138108109 is about 11751.9406482504. The cubic root of 138108109 is about 516.8998343111.

The spelling of 138108109 in words is "one hundred thirty-eight million, one hundred eight thousand, one hundred nine".