138520478 has 8 divisors (see below), whose sum is σ = 207835320. Its totient is φ = 69242040.

The previous prime is 138520457. The next prime is 138520537. The reversal of 138520478 is 874025831.

138520478 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

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 3 ways as a sum of consecutive naturals, for example, 4448 + ... + 17228.

It is an arithmetic number, because the mean of its divisors is an integer number (25979415).

Almost surely, 2^138520478 is an apocalyptic number.

138520478 is a deficient number, since it is larger than the sum of its proper divisors (69314842).

138520478 is a wasteful number, since it uses less digits than its factorization.

138520478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18202.

The product of its (nonzero) digits is 53760, while the sum is 38.

The square root of 138520478 is about 11769.4722906339. The cubic root of 138520478 is about 517.4137835475.

The spelling of 138520478 in words is "one hundred thirty-eight million, five hundred twenty thousand, four hundred seventy-eight".