138439859 has 2 divisors, whose sum is σ = 138439860. Its totient is φ = 138439858.

The previous prime is 138439817. The next prime is 138439867. The reversal of 138439859 is 958934831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138439859 - 2⁸ = 138439603 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138439879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69219929 + 69219930.

It is an arithmetic number, because the mean of its divisors is an integer number (69219930).

Almost surely, 2^138439859 is an apocalyptic number.

138439859 is a deficient number, since it is larger than the sum of its proper divisors (1).

138439859 is an equidigital number, since it uses as much as digits as its factorization.

138439859 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 933120, while the sum is 50.

The square root of 138439859 is about 11766.0468722507. The cubic root of 138439859 is about 517.3133856919.

The spelling of 138439859 in words is "one hundred thirty-eight million, four hundred thirty-nine thousand, eight hundred fifty-nine".