138223678 has 4 divisors (see below), whose sum is σ = 207335520. Its totient is φ = 69111838.

The previous prime is 138223661. The next prime is 138223681. The reversal of 138223678 is 876322831.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 138223678.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34555918 + ... + 34555921.

It is an arithmetic number, because the mean of its divisors is an integer number (51833880).

Almost surely, 2^138223678 is an apocalyptic number.

138223678 is a deficient number, since it is larger than the sum of its proper divisors (69111842).

138223678 is an equidigital number, since it uses as much as digits as its factorization.

138223678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69111841.

The product of its digits is 96768, while the sum is 40.

The square root of 138223678 is about 11756.8566377242. The cubic root of 138223678 is about 517.0439748744.

The spelling of 138223678 in words is "one hundred thirty-eight million, two hundred twenty-three thousand, six hundred seventy-eight".