138864189 has 4 divisors (see below), whose sum is σ = 185152256. Its totient is φ = 92576124.

The previous prime is 138864181. The next prime is 138864223. The reversal of 138864189 is 981468831.

138864189 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 Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 138864189 - 2³ = 138864181 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 (138864181) 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, 23144029 + ... + 23144034.

It is an arithmetic number, because the mean of its divisors is an integer number (46288064).

Almost surely, 2^138864189 is an apocalyptic number.

It is an amenable number.

138864189 is a deficient number, since it is larger than the sum of its proper divisors (46288067).

138864189 is an equidigital number, since it uses as much as digits as its factorization.

138864189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46288066.

The product of its digits is 331776, while the sum is 48.

The square root of 138864189 is about 11784.0650456453. The cubic root of 138864189 is about 517.8413831866.

The spelling of 138864189 in words is "one hundred thirty-eight million, eight hundred sixty-four thousand, one hundred eighty-nine".