138431289 has 12 divisors (see below), whose sum is σ = 196072304. Its totient is φ = 86858304.

The previous prime is 138431243. The next prime is 138431291. The reversal of 138431289 is 982134831.

It is not a de Polignac number, because 138431289 - 2¹³ = 138423097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138431789) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78967 + ... + 80700.

Almost surely, 2^138431289 is an apocalyptic number.

It is an amenable number.

138431289 is a deficient number, since it is larger than the sum of its proper divisors (57641015).

138431289 is a wasteful number, since it uses less digits than its factorization.

138431289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159704 (or 159687 counting only the distinct ones).

The product of its digits is 41472, while the sum is 39.

The square root of 138431289 is about 11765.6826831255. The cubic root of 138431289 is about 517.3027108587.

The spelling of 138431289 in words is "one hundred thirty-eight million, four hundred thirty-one thousand, two hundred eighty-nine".