138634665851 has 32 divisors (see below), whose sum is σ = 157751928000. Its totient is φ = 120677921280.

The previous prime is 138634665791. The next prime is 138634665853. The reversal of 138634665851 is 158566436831.

138634665851 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 138634665851 - 2¹⁸ = 138634403707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138634665853) 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 31 ways as a sum of consecutive naturals, for example, 35979041 + ... + 35982893.

It is an arithmetic number, because the mean of its divisors is an integer number (4929747750).

Almost surely, 2^138634665851 is an apocalyptic number.

138634665851 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138634665851 is a deficient number, since it is larger than the sum of its proper divisors (19117262149).

138634665851 is a wasteful number, since it uses less digits than its factorization.

138634665851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4799.

The product of its digits is 12441600, while the sum is 56.

The spelling of 138634665851 in words is "one hundred thirty-eight billion, six hundred thirty-four million, six hundred sixty-five thousand, eight hundred fifty-one".