138308940 has 288 divisors, whose sum is σ = 554770944. Its totient is φ = 27002880.

The previous prime is 138308927. The next prime is 138308953. The reversal of 138308940 is 49803831.

138308940 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (138308927) and next prime (138308953).

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 = 138308895 and 138308904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 235327 + ... + 235913.

It is an arithmetic number, because the mean of its divisors is an integer number (1926288).

Almost surely, 2^138308940 is an apocalyptic number.

138308940 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 138308940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277385472).

138308940 is an abundant number, since it is smaller than the sum of its proper divisors (416462004).

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

138308940 is a wasteful number, since it uses less digits than its factorization.

138308940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637 (or 632 counting only the distinct ones).

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

The square root of 138308940 is about 11760.4821329740. The cubic root of 138308940 is about 517.1502642907.

The spelling of 138308940 in words is "one hundred thirty-eight million, three hundred eight thousand, nine hundred forty".