138394823 has 4 divisors (see below), whose sum is σ = 158165520. Its totient is φ = 118624128.

The previous prime is 138394813. The next prime is 138394843. The reversal of 138394823 is 328493831.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 138394823 - 2⁶ = 138394759 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 (138394813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9885338 + ... + 9885351.

It is an arithmetic number, because the mean of its divisors is an integer number (39541380).

Almost surely, 2^138394823 is an apocalyptic number.

138394823 is a deficient number, since it is larger than the sum of its proper divisors (19770697).

138394823 is an equidigital number, since it uses as much as digits as its factorization.

138394823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19770696.

The product of its digits is 124416, while the sum is 41.

The square root of 138394823 is about 11764.1329047236. The cubic root of 138394823 is about 517.2572837075.

The spelling of 138394823 in words is "one hundred thirty-eight million, three hundred ninety-four thousand, eight hundred twenty-three".