138039305 has 4 divisors (see below), whose sum is σ = 165647172. Its totient is φ = 110431440.

The previous prime is 138039301. The next prime is 138039323. The reversal of 138039305 is 503930831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 503930831 = 647 ⋅778873.

It can be written as a sum of positive squares in 2 ways, for example, as 94848121 + 43191184 = 9739^2 + 6572^2 .

It is not a de Polignac number, because 138039305 - 2² = 138039301 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138039301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13803926 + ... + 13803935.

It is an arithmetic number, because the mean of its divisors is an integer number (41411793).

Almost surely, 2^138039305 is an apocalyptic number.

It is an amenable number.

138039305 is a deficient number, since it is larger than the sum of its proper divisors (27607867).

138039305 is an equidigital number, since it uses as much as digits as its factorization.

138039305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27607866.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 138039305 is about 11749.0129372641. The cubic root of 138039305 is about 516.8139820415.

The spelling of 138039305 in words is "one hundred thirty-eight million, thirty-nine thousand, three hundred five".