138921876 has 18 divisors (see below), whose sum is σ = 351163722. Its totient is φ = 46307280.

The previous prime is 138921859. The next prime is 138921883. The reversal of 138921876 is 678129831.

It can be written as a sum of positive squares in only one way, i.e., 112911876 + 26010000 = 10626^2 + 5100^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 1929435 + ... + 1929506.

Almost surely, 2^138921876 is an apocalyptic number.

It is an amenable number.

138921876 is an abundant number, since it is smaller than the sum of its proper divisors (212241846).

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

138921876 is a wasteful number, since it uses less digits than its factorization.

138921876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3858951 (or 3858946 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 138921876 is about 11786.5124612839. The cubic root of 138921876 is about 517.9130805298.

The spelling of 138921876 in words is "one hundred thirty-eight million, nine hundred twenty-one thousand, eight hundred seventy-six".