138439206 has 80 divisors (see below), whose sum is σ = 334802160. Its totient is φ = 42612480.

The previous prime is 138439199. The next prime is 138439207. The reversal of 138439206 is 602934831.

138439206 is a `hidden beast` number, since 13 + 8 + 439 + 206 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138439207) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 125650 + ... + 126746.

It is an arithmetic number, because the mean of its divisors is an integer number (4185027).

Almost surely, 2^138439206 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138439206, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167401080).

138439206 is an abundant number, since it is smaller than the sum of its proper divisors (196362954).

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

138439206 is a wasteful number, since it uses less digits than its factorization.

138439206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171 (or 1162 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 138439206 is about 11766.0191228809. The cubic root of 138439206 is about 517.3125723275.

The spelling of 138439206 in words is "one hundred thirty-eight million, four hundred thirty-nine thousand, two hundred six".