138685608 has 40 divisors (see below), whose sum is σ = 388449930. Its totient is φ = 46228320.

The previous prime is 138685601. The next prime is 138685633. The reversal of 138685608 is 806586831.

138685608 is a `hidden beast` number, since 1 + 3 + 86 + 8 + 560 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 133125444 + 5560164 = 11538^2 + 2358^2 .

It is not an unprimeable number, because it can be changed into a prime (138685601) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 106363 + ... + 107658.

Almost surely, 2^138685608 is an apocalyptic number.

138685608 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138685608 is an abundant number, since it is smaller than the sum of its proper divisors (249764322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138685608 is a wasteful number, since it uses less digits than its factorization.

138685608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214039 (or 214026 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 138685608 is about 11776.4853840184. The cubic root of 138685608 is about 517.6193045665.

The spelling of 138685608 in words is "one hundred thirty-eight million, six hundred eighty-five thousand, six hundred eight".