138321000 has 256 divisors, whose sum is σ = 494208000. Its totient is φ = 35769600.

The previous prime is 138320971. The next prime is 138321013. The reversal of 138321000 is 123831.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1268946 + ... + 1269054.

It is an arithmetic number, because the mean of its divisors is an integer number (1930500).

Almost surely, 2^138321000 is an apocalyptic number.

138321000 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 138321000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247104000).

138321000 is an abundant number, since it is smaller than the sum of its proper divisors (355887000).

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

138321000 is a wasteful number, since it uses less digits than its factorization.

138321000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 138321000 is about 11760.9948558785. The cubic root of 138321000 is about 517.1652950157.

Adding to 138321000 its reverse (123831), we get a palindrome (138444831).

The spelling of 138321000 in words is "one hundred thirty-eight million, three hundred twenty-one thousand".