138555309 has 8 divisors (see below), whose sum is σ = 184796640. Its totient is φ = 92342096.

The previous prime is 138555299. The next prime is 138555341. The reversal of 138555309 is 903555831.

It is a happy number.

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 138555309 - 2⁹ = 138554797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138555509) 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 in 7 ways as a sum of consecutive naturals, for example, 11302 + ... + 20120.

It is an arithmetic number, because the mean of its divisors is an integer number (23099580).

Almost surely, 2^138555309 is an apocalyptic number.

It is an amenable number.

138555309 is a deficient number, since it is larger than the sum of its proper divisors (46241331).

138555309 is an equidigital number, since it uses as much as digits as its factorization.

138555309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14059.

The product of its (nonzero) digits is 81000, while the sum is 39.

The square root of 138555309 is about 11770.9519156269. The cubic root of 138555309 is about 517.4571478438.

The spelling of 138555309 in words is "one hundred thirty-eight million, five hundred fifty-five thousand, three hundred nine".