138768665 has 8 divisors (see below), whose sum is σ = 190311360. Its totient is φ = 95155632.

The previous prime is 138768653. The next prime is 138768667. The reversal of 138768665 is 566867831.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138768665 - 2⁶ = 138768601 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138768667) 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, 1982375 + ... + 1982444.

It is an arithmetic number, because the mean of its divisors is an integer number (23788920).

Almost surely, 2^138768665 is an apocalyptic number.

It is an amenable number.

138768665 is a deficient number, since it is larger than the sum of its proper divisors (51542695).

138768665 is an equidigital number, since it uses as much as digits as its factorization.

138768665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3964831.

The product of its digits is 1451520, while the sum is 50.

The square root of 138768665 is about 11780.0112478724. The cubic root of 138768665 is about 517.7226157599.

It can be divided in two parts, 13 and 8768665, that added together give a palindrome (8768678).

The spelling of 138768665 in words is "one hundred thirty-eight million, seven hundred sixty-eight thousand, six hundred sixty-five".