163881718789 has 2 divisors, whose sum is σ = 163881718790. Its totient is φ = 163881718788.

The previous prime is 163881718757. The next prime is 163881718811. The reversal of 163881718789 is 987817188361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155663389764 + 8218329025 = 394542^2 + 90655^2 .

It is a cyclic number.

It is not a de Polignac number, because 163881718789 - 2⁵ = 163881718757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163881218789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81940859394 + 81940859395.

It is an arithmetic number, because the mean of its divisors is an integer number (81940859395).

Almost surely, 2^163881718789 is an apocalyptic number.

It is an amenable number.

163881718789 is a deficient number, since it is larger than the sum of its proper divisors (1).

163881718789 is an equidigital number, since it uses as much as digits as its factorization.

163881718789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32514048, while the sum is 67.

The spelling of 163881718789 in words is "one hundred sixty-three billion, eight hundred eighty-one million, seven hundred eighteen thousand, seven hundred eighty-nine".