138739688 has 8 divisors (see below), whose sum is σ = 260136930. Its totient is φ = 69369840.

The previous prime is 138739633. The next prime is 138739717. The reversal of 138739688 is 886937831.

It can be written as a sum of positive squares in only one way, i.e., 127193284 + 11546404 = 11278^2 + 3398^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8671223 + ... + 8671238.

Almost surely, 2^138739688 is an apocalyptic number.

It is an amenable number.

138739688 is a deficient number, since it is larger than the sum of its proper divisors (121397242).

138739688 is a wasteful number, since it uses less digits than its factorization.

138739688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17342467 (or 17342463 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 53.

The square root of 138739688 is about 11778.7812612341. The cubic root of 138739688 is about 517.6865771422.

The spelling of 138739688 in words is "one hundred thirty-eight million, seven hundred thirty-nine thousand, six hundred eighty-eight".