138661389161 has 2 divisors, whose sum is σ = 138661389162. Its totient is φ = 138661389160.

The previous prime is 138661389143. The next prime is 138661389179. The reversal of 138661389161 is 161983166831.

It is a balanced prime because it is at equal distance from previous prime (138661389143) and next prime (138661389179).

It can be written as a sum of positive squares in only one way, i.e., 134685330025 + 3976059136 = 366995^2 + 63056^2 .

It is a cyclic number.

It is not a de Polignac number, because 138661389161 - 2¹⁴ = 138661372777 is a prime.

It is not a weakly prime, because it can be changed into another prime (138661389121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69330694580 + 69330694581.

It is an arithmetic number, because the mean of its divisors is an integer number (69330694581).

Almost surely, 2^138661389161 is an apocalyptic number.

It is an amenable number.

138661389161 is a deficient number, since it is larger than the sum of its proper divisors (1).

138661389161 is an equidigital number, since it uses as much as digits as its factorization.

138661389161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1119744, while the sum is 53.

The spelling of 138661389161 in words is "one hundred thirty-eight billion, six hundred sixty-one million, three hundred eighty-nine thousand, one hundred sixty-one".