138666386651 has 16 divisors (see below), whose sum is σ = 149566846464. Its totient is φ = 127799506944.

The previous prime is 138666386647. The next prime is 138666386693. The reversal of 138666386651 is 156683666831.

It is a cyclic number.

It is not a de Polignac number, because 138666386651 - 2² = 138666386647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138666586651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38335595 + ... + 38339211.

It is an arithmetic number, because the mean of its divisors is an integer number (9347927904).

Almost surely, 2^138666386651 is an apocalyptic number.

138666386651 is a deficient number, since it is larger than the sum of its proper divisors (10900459813).

138666386651 is a wasteful number, since it uses less digits than its factorization.

138666386651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7430.

The product of its digits is 22394880, while the sum is 59.

The spelling of 138666386651 in words is "one hundred thirty-eight billion, six hundred sixty-six million, three hundred eighty-six thousand, six hundred fifty-one".