138133908 has 144 divisors (see below), whose sum is σ = 410417280. Its totient is φ = 38841600.

The previous prime is 138133907. The next prime is 138133909. The reversal of 138133908 is 809331831.

It is an interprime number because it is at equal distance from previous prime (138133907) and next prime (138133909).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138133901) 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, 1945513 + ... + 1945583.

It is an arithmetic number, because the mean of its divisors is an integer number (2850120).

Almost surely, 2^138133908 is an apocalyptic number.

138133908 is a gapful number since it is divisible by the number (18) 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 138133908, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (205208640).

138133908 is an abundant number, since it is smaller than the sum of its proper divisors (272283372).

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

138133908 is a wasteful number, since it uses less digits than its factorization.

138133908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 138133908 is about 11753.0382454921. The cubic root of 138133908 is about 516.9320184424.

The spelling of 138133908 in words is "one hundred thirty-eight million, one hundred thirty-three thousand, nine hundred eight".