138689817 has 24 divisors (see below), whose sum is σ = 215936064. Its totient is φ = 77535744.

The previous prime is 138689813. The next prime is 138689833. The reversal of 138689817 is 718986831.

It is not a de Polignac number, because 138689817 - 2² = 138689813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138689817.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138689813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 392713 + ... + 393065.

It is an arithmetic number, because the mean of its divisors is an integer number (8997336).

Almost surely, 2^138689817 is an apocalyptic number.

It is an amenable number.

138689817 is a deficient number, since it is larger than the sum of its proper divisors (77246247).

138689817 is an frugal number, since it uses more digits than its factorization.

138689817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 769 (or 416 counting only the distinct ones).

The product of its digits is 580608, while the sum is 51.

The square root of 138689817 is about 11776.6640862343. The cubic root of 138689817 is about 517.6245409609.

The spelling of 138689817 in words is "one hundred thirty-eight million, six hundred eighty-nine thousand, eight hundred seventeen".