138839040 has 264 divisors, whose sum is σ = 505821888. Its totient is φ = 35143680.

The previous prime is 138839039. The next prime is 138839047. The reversal of 138839040 is 40938831.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 138838986 and 138839004.

It is not an unprimeable number, because it can be changed into a prime (138839047) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1059775 + ... + 1059905.

It is an arithmetic number, because the mean of its divisors is an integer number (1915992).

Almost surely, 2^138839040 is an apocalyptic number.

138839040 is a gapful number since it is divisible by the number (10) 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 138839040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252910944).

138839040 is an abundant number, since it is smaller than the sum of its proper divisors (366982848).

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

138839040 is a wasteful number, since it uses less digits than its factorization.

138839040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 138839040 is about 11782.9979207331. The cubic root of 138839040 is about 517.8101200766.

The spelling of 138839040 in words is "one hundred thirty-eight million, eight hundred thirty-nine thousand, forty".