138684686 has 32 divisors (see below), whose sum is σ = 255605760. Its totient is φ = 55105056.

The previous prime is 138684661. The next prime is 138684709. The reversal of 138684686 is 686486831.

It is a happy number.

It is a super-4 number, since 4×138684686⁴ (a number of 34 digits) contains 4444 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6956 + ... + 18048.

It is an arithmetic number, because the mean of its divisors is an integer number (7987680).

Almost surely, 2^138684686 is an apocalyptic number.

138684686 is a deficient number, since it is larger than the sum of its proper divisors (116921074).

138684686 is a wasteful number, since it uses less digits than its factorization.

138684686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11168.

The product of its digits is 1327104, while the sum is 50.

The square root of 138684686 is about 11776.4462381484. The cubic root of 138684686 is about 517.6181574971.

The spelling of 138684686 in words is "one hundred thirty-eight million, six hundred eighty-four thousand, six hundred eighty-six".