138706728 has 16 divisors (see below), whose sum is σ = 346766880. Its totient is φ = 46235568.

The previous prime is 138706727. The next prime is 138706753. The reversal of 138706728 is 827607831.

It is a self number, because there is not a number n which added to its sum of digits gives 138706728.

It is not an unprimeable number, because it can be changed into a prime (138706727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2889700 + ... + 2889747.

It is an arithmetic number, because the mean of its divisors is an integer number (21672930).

Almost surely, 2^138706728 is an apocalyptic number.

It is an amenable number.

138706728 is an abundant number, since it is smaller than the sum of its proper divisors (208060152).

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

138706728 is a wasteful number, since it uses less digits than its factorization.

138706728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5779456 (or 5779452 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 42.

The square root of 138706728 is about 11777.3820520521. The cubic root of 138706728 is about 517.6455787776.

The spelling of 138706728 in words is "one hundred thirty-eight million, seven hundred six thousand, seven hundred twenty-eight".