138641328 has 240 divisors, whose sum is σ = 483778560. Its totient is φ = 37231488.

The previous prime is 138641303. The next prime is 138641329. The reversal of 138641328 is 823146831.

138641328 is a `hidden beast` number, since 1 + 3 + 8 + 641 + 3 + 2 + 8 = 666.

138641328 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 138641292 and 138641301.

It is not an unprimeable number, because it can be changed into a prime (138641329) 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, 1091601 + ... + 1091727.

It is an arithmetic number, because the mean of its divisors is an integer number (2015744).

Almost surely, 2^138641328 is an apocalyptic number.

138641328 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 138641328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241889280).

138641328 is an abundant number, since it is smaller than the sum of its proper divisors (345137232).

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

138641328 is a wasteful number, since it uses less digits than its factorization.

138641328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189 (or 158 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 138641328 is about 11774.6052163119. The cubic root of 138641328 is about 517.5642096341.

The spelling of 138641328 in words is "one hundred thirty-eight million, six hundred forty-one thousand, three hundred twenty-eight".