138189231 has 6 divisors (see below), whose sum is σ = 199606680. Its totient is φ = 92126148.

The previous prime is 138189211. The next prime is 138189283. The reversal of 138189231 is 132981831.

It is not a de Polignac number, because 138189231 - 2¹³ = 138181039 is a prime.

It is a super-2 number, since 2×138189231² = 38192527128742722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138189211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7677171 + ... + 7677188.

It is an arithmetic number, because the mean of its divisors is an integer number (33267780).

Almost surely, 2^138189231 is an apocalyptic number.

138189231 is a deficient number, since it is larger than the sum of its proper divisors (61417449).

138189231 is a wasteful number, since it uses less digits than its factorization.

138189231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15354365 (or 15354362 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 138189231 is about 11755.3915715301. The cubic root of 138189231 is about 517.0010201173.

The spelling of 138189231 in words is "one hundred thirty-eight million, one hundred eighty-nine thousand, two hundred thirty-one".