138539009 has 8 divisors (see below), whose sum is σ = 158591040. Its totient is φ = 118552176.

The previous prime is 138538997. The next prime is 138539047. The reversal of 138539009 is 900935831.

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 138539009 - 2²⁰ = 137490433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138539059) 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, 11654 + ... + 20319.

It is an arithmetic number, because the mean of its divisors is an integer number (19823880).

Almost surely, 2^138539009 is an apocalyptic number.

It is an amenable number.

138539009 is a deficient number, since it is larger than the sum of its proper divisors (20052031).

138539009 is an equidigital number, since it uses as much as digits as its factorization.

138539009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32599.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 138539009 is about 11770.2595128570. The cubic root of 138539009 is about 517.4368553884.

The spelling of 138539009 in words is "one hundred thirty-eight million, five hundred thirty-nine thousand, nine".