138389706 has 144 divisors (see below), whose sum is σ = 380487744. Its totient is φ = 35582976.

The previous prime is 138389701. The next prime is 138389717. The reversal of 138389706 is 607983831.

It is a happy number.

138389706 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (138389701) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1426650 + ... + 1426746.

It is an arithmetic number, because the mean of its divisors is an integer number (2642276).

Almost surely, 2^138389706 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138389706, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190243872).

138389706 is an abundant number, since it is smaller than the sum of its proper divisors (242098038).

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

138389706 is a wasteful number, since it uses less digits than its factorization.

138389706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 189 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 138389706 is about 11763.9154196211. The cubic root of 138389706 is about 517.2509086180.

The spelling of 138389706 in words is "one hundred thirty-eight million, three hundred eighty-nine thousand, seven hundred six".