138240168 has 32 divisors (see below), whose sum is σ = 377019360. Its totient is φ = 41890880.

The previous prime is 138240163. The next prime is 138240169. The reversal of 138240168 is 861042831.

It is a super-2 number, since 2×138240168² = 38220688097336448, which contains 22 as substring.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (138240163) 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 7 ways as a sum of consecutive naturals, for example, 261555 + ... + 262082.

It is an arithmetic number, because the mean of its divisors is an integer number (11781855).

Almost surely, 2^138240168 is an apocalyptic number.

It is an amenable number.

138240168 is an abundant number, since it is smaller than the sum of its proper divisors (238779192).

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

138240168 is a wasteful number, since it uses less digits than its factorization.

138240168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523657 (or 523653 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 138240168 is about 11757.5579097022. The cubic root of 138240168 is about 517.0645350665.

Adding to 138240168 its reverse (861042831), we get a palindrome (999282999).

The spelling of 138240168 in words is "one hundred thirty-eight million, two hundred forty thousand, one hundred sixty-eight".