138989309 has 8 divisors (see below), whose sum is σ = 142290240. Its totient is φ = 135720000.

The previous prime is 138989281. The next prime is 138989317. The reversal of 138989309 is 903989831.

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 138989309 - 2²⁴ = 122212093 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138989329) 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, 1109 + ... + 16709.

It is an arithmetic number, because the mean of its divisors is an integer number (17786280).

Almost surely, 2^138989309 is an apocalyptic number.

It is an amenable number.

138989309 is a deficient number, since it is larger than the sum of its proper divisors (3300931).

138989309 is a wasteful number, since it uses less digits than its factorization.

138989309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15811.

The product of its (nonzero) digits is 419904, while the sum is 50.

The square root of 138989309 is about 11789.3727144407. The cubic root of 138989309 is about 517.9968657105.

The spelling of 138989309 in words is "one hundred thirty-eight million, nine hundred eighty-nine thousand, three hundred nine".