138784238 has 4 divisors (see below), whose sum is σ = 208176360. Its totient is φ = 69392118.

The previous prime is 138784237. The next prime is 138784253. The reversal of 138784238 is 832487831.

It is a happy number.

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

It is a super-2 number, since 2×138784238² = 38522129434481288, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138784237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34696058 + ... + 34696061.

It is an arithmetic number, because the mean of its divisors is an integer number (52044090).

Almost surely, 2^138784238 is an apocalyptic number.

138784238 is a deficient number, since it is larger than the sum of its proper divisors (69392122).

138784238 is an equidigital number, since it uses as much as digits as its factorization.

138784238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69392121.

The product of its digits is 258048, while the sum is 44.

The square root of 138784238 is about 11780.6722219065. The cubic root of 138784238 is about 517.7419817858.

The spelling of 138784238 in words is "one hundred thirty-eight million, seven hundred eighty-four thousand, two hundred thirty-eight".