138000000 has 224 divisors, whose sum is σ = 478118880. Its totient is φ = 35200000.

The previous prime is 137999987. The next prime is 138000001. The reversal of 138000000 is 831.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 138000000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138000001) 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 27 ways as a sum of consecutive naturals, for example, 5999989 + ... + 6000011.

Almost surely, 2^138000000 is an apocalyptic number.

138000000 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 138000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239059440).

138000000 is an abundant number, since it is smaller than the sum of its proper divisors (340118880).

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

138000000 is an frugal number, since it uses more digits than its factorization.

138000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70 (or 33 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 138000000 is about 11747.3401244707. The cubic root of 138000000 is about 516.7649252364.

Adding to 138000000 its reverse (831), we get a palindrome (138000831).

The spelling of 138000000 in words is "one hundred thirty-eight million", and thus it is an aban number.