138665420767 has 4 divisors (see below), whose sum is σ = 138729590176. Its totient is φ = 138601251360.

The previous prime is 138665420743. The next prime is 138665420783. The reversal of 138665420767 is 767024566831.

138665420767 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138665420767 - 2⁷ = 138665420639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138665420737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32081463 + ... + 32085784.

It is an arithmetic number, because the mean of its divisors is an integer number (34682397544).

Almost surely, 2^138665420767 is an apocalyptic number.

138665420767 is a deficient number, since it is larger than the sum of its proper divisors (64169409).

138665420767 is an equidigital number, since it uses as much as digits as its factorization.

138665420767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64169408.

The product of its (nonzero) digits is 10160640, while the sum is 55.

The spelling of 138665420767 in words is "one hundred thirty-eight billion, six hundred sixty-five million, four hundred twenty thousand, seven hundred sixty-seven".