138698909 has 8 divisors (see below), whose sum is σ = 143616000. Its totient is φ = 133790832.

The previous prime is 138698881. The next prime is 138698921. The reversal of 138698909 is 909896831.

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 138698909 - 2²⁴ = 121921693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138698969) 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, 49652 + ... + 52370.

It is an arithmetic number, because the mean of its divisors is an integer number (17952000).

Almost surely, 2^138698909 is an apocalyptic number.

It is an amenable number.

138698909 is a deficient number, since it is larger than the sum of its proper divisors (4917091).

138698909 is a wasteful number, since it uses less digits than its factorization.

138698909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4507.

The product of its (nonzero) digits is 839808, while the sum is 53.

The square root of 138698909 is about 11777.0500975414. The cubic root of 138698909 is about 517.6358519078.

The spelling of 138698909 in words is "one hundred thirty-eight million, six hundred ninety-eight thousand, nine hundred nine".