138727289 has 4 divisors (see below), whose sum is σ = 138753024. Its totient is φ = 138701556.

The previous prime is 138727273. The next prime is 138727291. The reversal of 138727289 is 982727831.

138727289 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 a cyclic number.

It is not a de Polignac number, because 138727289 - 2⁴ = 138727273 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138727219) 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, 1337 + ... + 16710.

It is an arithmetic number, because the mean of its divisors is an integer number (34688256).

Almost surely, 2^138727289 is an apocalyptic number.

It is an amenable number.

138727289 is a deficient number, since it is larger than the sum of its proper divisors (25735).

138727289 is an equidigital number, since it uses as much as digits as its factorization.

138727289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25734.

The product of its digits is 338688, while the sum is 47.

The square root of 138727289 is about 11778.2549216766. The cubic root of 138727289 is about 517.6711550060.

The spelling of 138727289 in words is "one hundred thirty-eight million, seven hundred twenty-seven thousand, two hundred eighty-nine".