138435984 has 60 divisors (see below), whose sum is σ = 389738076. Its totient is φ = 45870336.

The previous prime is 138435931. The next prime is 138435989. The reversal of 138435984 is 489534831.

138435984 is a `hidden beast` number, since 13 + 8 + 43 + 598 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 128323584 + 10112400 = 11328^2 + 3180^2 .

It is not an unprimeable number, because it can be changed into a prime (138435989) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22134 + ... + 27690.

Almost surely, 2^138435984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138435984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194869038).

138435984 is an abundant number, since it is smaller than the sum of its proper divisors (251302092).

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

138435984 is a wasteful number, since it uses less digits than its factorization.

138435984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5744 (or 5735 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 138435984 is about 11765.8822023680. The cubic root of 138435984 is about 517.3085590278.

The spelling of 138435984 in words is "one hundred thirty-eight million, four hundred thirty-five thousand, nine hundred eighty-four".