138138138 has 24 divisors (see below), whose sum is σ = 312313248. Its totient is φ = 44043912.

The previous prime is 138138127. The next prime is 138138191. The reversal of 138138138 is 831831831.

138138138 is a modest number, since divided by 138138 gives 138 as remainder.

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 11 ways as a sum of consecutive naturals, for example, 166420 + ... + 167247.

It is an arithmetic number, because the mean of its divisors is an integer number (13013052).

Almost surely, 2^138138138 is an apocalyptic number.

138138138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

138138138 is an abundant number, since it is smaller than the sum of its proper divisors (174175110).

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

138138138 is a wasteful number, since it uses less digits than its factorization.

138138138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333698 (or 333695 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 138138138 is about 11753.2181975832. The cubic root of 138138138 is about 516.9372949652.

Adding to 138138138 its reverse (831831831), we get a palindrome (969969969).

The spelling of 138138138 in words is "one hundred thirty-eight million, one hundred thirty-eight thousand, one hundred thirty-eight".