138888823 has 4 divisors (see below), whose sum is σ = 138912400. Its totient is φ = 138865248.

The previous prime is 138888791. The next prime is 138888829. The reversal of 138888823 is 328888831.

138888823 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 328888831 = 1489 ⋅220879.

It is a cyclic number.

It is not a de Polignac number, because 138888823 - 2⁵ = 138888791 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 (138888829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5503 + ... + 17551.

It is an arithmetic number, because the mean of its divisors is an integer number (34728100).

Almost surely, 2^138888823 is an apocalyptic number.

138888823 is a deficient number, since it is larger than the sum of its proper divisors (23577).

138888823 is a wasteful number, since it uses less digits than its factorization.

138888823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23576.

The product of its digits is 589824, while the sum is 49.

The square root of 138888823 is about 11785.1102243467. The cubic root of 138888823 is about 517.8720024328.

The spelling of 138888823 in words is "one hundred thirty-eight million, eight hundred eighty-eight thousand, eight hundred twenty-three".