138231238 has 4 divisors (see below), whose sum is σ = 207346860. Its totient is φ = 69115618.

The previous prime is 138231229. The next prime is 138231239. The reversal of 138231238 is 832132831.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138231239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34557808 + ... + 34557811.

It is an arithmetic number, because the mean of its divisors is an integer number (51836715).

Almost surely, 2^138231238 is an apocalyptic number.

138231238 is a deficient number, since it is larger than the sum of its proper divisors (69115622).

138231238 is an equidigital number, since it uses as much as digits as its factorization.

138231238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69115621.

The product of its digits is 6912, while the sum is 31.

The square root of 138231238 is about 11757.1781478380. The cubic root of 138231238 is about 517.0534010963.

The spelling of 138231238 in words is "one hundred thirty-eight million, two hundred thirty-one thousand, two hundred thirty-eight".