138209328 has 100 divisors (see below), whose sum is σ = 408708960. Its totient is φ = 45069696.

The previous prime is 138209327. The next prime is 138209339. The reversal of 138209328 is 823902831.

It is a happy number.

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 = 138209292 and 138209301.

It is not an unprimeable number, because it can be changed into a prime (138209321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 59778 + ... + 62046.

Almost surely, 2^138209328 is an apocalyptic number.

138209328 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 138209328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (204354480).

138209328 is an abundant number, since it is smaller than the sum of its proper divisors (270499632).

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

138209328 is a wasteful number, since it uses less digits than its factorization.

138209328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2336 (or 2321 counting only the distinct ones).

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

The square root of 138209328 is about 11756.2463397123. The cubic root of 138209328 is about 517.0260815633.

The spelling of 138209328 in words is "one hundred thirty-eight million, two hundred nine thousand, three hundred twenty-eight".