138559217 has 2 divisors, whose sum is σ = 138559218. Its totient is φ = 138559216.

The previous prime is 138559177. The next prime is 138559219. The reversal of 138559217 is 712955831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128165041 + 10394176 = 11321^2 + 3224^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138559217 is a prime.

Together with 138559219, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138559219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69279608 + 69279609.

It is an arithmetic number, because the mean of its divisors is an integer number (69279609).

Almost surely, 2^138559217 is an apocalyptic number.

It is an amenable number.

138559217 is a deficient number, since it is larger than the sum of its proper divisors (1).

138559217 is an equidigital number, since it uses as much as digits as its factorization.

138559217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75600, while the sum is 41.

The square root of 138559217 is about 11771.1179163238. The cubic root of 138559217 is about 517.4620128168.

The spelling of 138559217 in words is "one hundred thirty-eight million, five hundred fifty-nine thousand, two hundred seventeen".