138536609 has 2 divisors, whose sum is σ = 138536610. Its totient is φ = 138536608.

The previous prime is 138536603. The next prime is 138536633. The reversal of 138536609 is 906635831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136773025 + 1763584 = 11695^2 + 1328^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138536609 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138536603) 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, 69268304 + 69268305.

It is an arithmetic number, because the mean of its divisors is an integer number (69268305).

Almost surely, 2^138536609 is an apocalyptic number.

It is an amenable number.

138536609 is a deficient number, since it is larger than the sum of its proper divisors (1).

138536609 is an equidigital number, since it uses as much as digits as its factorization.

138536609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 138536609 is about 11770.1575605427. The cubic root of 138536609 is about 517.4338674077.

The spelling of 138536609 in words is "one hundred thirty-eight million, five hundred thirty-six thousand, six hundred nine".