138689938 has 4 divisors (see below), whose sum is σ = 208034910. Its totient is φ = 69344968.

The previous prime is 138689917. The next prime is 138689953. The reversal of 138689938 is 839986831.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 110313009 + 28376929 = 10503^2 + 5327^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34672483 + ... + 34672486.

Almost surely, 2^138689938 is an apocalyptic number.

138689938 is a deficient number, since it is larger than the sum of its proper divisors (69344972).

138689938 is an equidigital number, since it uses as much as digits as its factorization.

138689938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69344971.

The product of its digits is 2239488, while the sum is 55.

The square root of 138689938 is about 11776.6692235114. The cubic root of 138689938 is about 517.6246914947.

The spelling of 138689938 in words is "one hundred thirty-eight million, six hundred eighty-nine thousand, nine hundred thirty-eight".