138439092 has 144 divisors (see below), whose sum is σ = 396103680. Its totient is φ = 37209600.

The previous prime is 138439057. The next prime is 138439099. The reversal of 138439092 is 290934831.

It is a self number, because there is not a number n which added to its sum of digits gives 138439092.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138439099) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 724717 + ... + 724907.

It is an arithmetic number, because the mean of its divisors is an integer number (2750720).

Almost surely, 2^138439092 is an apocalyptic number.

138439092 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138439092, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198051840).

138439092 is an abundant number, since it is smaller than the sum of its proper divisors (257664588).

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

138439092 is a wasteful number, since it uses less digits than its factorization.

138439092 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 138439092 is about 11766.0142784207. The cubic root of 138439092 is about 517.3124303309.

The spelling of 138439092 in words is "one hundred thirty-eight million, four hundred thirty-nine thousand, ninety-two".