138606191 has 2 divisors, whose sum is σ = 138606192. Its totient is φ = 138606190.

The previous prime is 138606187. The next prime is 138606227. The reversal of 138606191 is 191606831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138606191 - 2² = 138606187 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 (138606131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69303095 + 69303096.

It is an arithmetic number, because the mean of its divisors is an integer number (69303096).

Almost surely, 2^138606191 is an apocalyptic number.

138606191 is a deficient number, since it is larger than the sum of its proper divisors (1).

138606191 is an equidigital number, since it uses as much as digits as its factorization.

138606191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 138606191 is about 11773.1130547532. The cubic root of 138606191 is about 517.5204824367.

The spelling of 138606191 in words is "one hundred thirty-eight million, six hundred six thousand, one hundred ninety-one".