138644047 has 8 divisors (see below), whose sum is σ = 139629600. Its totient is φ = 137662464.

The previous prime is 138644039. The next prime is 138644063. The reversal of 138644047 is 740446831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138644047 - 2³ = 138644039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138643997 and 138644015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138644017) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104454 + ... + 105772.

It is an arithmetic number, because the mean of its divisors is an integer number (17453700).

Almost surely, 2^138644047 is an apocalyptic number.

138644047 is a deficient number, since it is larger than the sum of its proper divisors (985553).

138644047 is a wasteful number, since it uses less digits than its factorization.

138644047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1985.

The product of its (nonzero) digits is 64512, while the sum is 37.

The square root of 138644047 is about 11774.7206760925. The cubic root of 138644047 is about 517.5675930598.

The spelling of 138644047 in words is "one hundred thirty-eight million, six hundred forty-four thousand, forty-seven".