138815009 has 8 divisors (see below), whose sum is σ = 142930920. Its totient is φ = 134718336.

The previous prime is 138814997. The next prime is 138815021. The reversal of 138815009 is 900518831.

It is an interprime number because it is at equal distance from previous prime (138814997) and next prime (138815021).

It can be written as a sum of positive squares in 4 ways, for example, as 38254225 + 100560784 = 6185^2 + 10028^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138815009 - 2¹² = 138810913 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138815009.

It is not an unprimeable number, because it can be changed into a prime (138815069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10547 + ... + 19719.

It is an arithmetic number, because the mean of its divisors is an integer number (17866365).

Almost surely, 2^138815009 is an apocalyptic number.

It is an amenable number.

138815009 is a deficient number, since it is larger than the sum of its proper divisors (4115911).

138815009 is an equidigital number, since it uses as much as digits as its factorization.

138815009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9619.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 138815009 is about 11781.9781446071. The cubic root of 138815009 is about 517.7802432423.

The spelling of 138815009 in words is "one hundred thirty-eight million, eight hundred fifteen thousand, nine".