138804109 has 2 divisors, whose sum is σ = 138804110. Its totient is φ = 138804108.

The previous prime is 138804091. The next prime is 138804151. The reversal of 138804109 is 901408831.

It is a happy number.

Together with previous prime (138804091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134792100 + 4012009 = 11610^2 + 2003^2 .

It is an emirp because it is prime and its reverse (901408831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138804109 - 2¹⁵ = 138771341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138804409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69402054 + 69402055.

It is an arithmetic number, because the mean of its divisors is an integer number (69402055).

Almost surely, 2^138804109 is an apocalyptic number.

It is an amenable number.

138804109 is a deficient number, since it is larger than the sum of its proper divisors (1).

138804109 is an equidigital number, since it uses as much as digits as its factorization.

138804109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 138804109 is about 11781.5155646462. The cubic root of 138804109 is about 517.7666905474.

The spelling of 138804109 in words is "one hundred thirty-eight million, eight hundred four thousand, one hundred nine".