138638678 has 8 divisors (see below), whose sum is σ = 211062072. Its totient is φ = 68284656.

The previous prime is 138638677. The next prime is 138638681. The reversal of 138638678 is 876836831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138638677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 517175 + ... + 517442.

It is an arithmetic number, because the mean of its divisors is an integer number (26382759).

Almost surely, 2^138638678 is an apocalyptic number.

138638678 is a deficient number, since it is larger than the sum of its proper divisors (72423394).

138638678 is a wasteful number, since it uses less digits than its factorization.

138638678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034686.

The product of its digits is 1161216, while the sum is 50.

The square root of 138638678 is about 11774.4926854621. The cubic root of 138638678 is about 517.5609120270.

The spelling of 138638678 in words is "one hundred thirty-eight million, six hundred thirty-eight thousand, six hundred seventy-eight".