13178320781 has 2 divisors, whose sum is σ = 13178320782. Its totient is φ = 13178320780.

The previous prime is 13178320759. The next prime is 13178320801. The reversal of 13178320781 is 18702387131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11874460900 + 1303859881 = 108970^2 + 36109^2 .

It is a cyclic number.

It is not a de Polignac number, because 13178320781 - 2⁶ = 13178320717 is a prime.

It is a super-2 number, since 2×13178320781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13171320781) 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 as a sum of consecutive naturals, namely, 6589160390 + 6589160391.

It is an arithmetic number, because the mean of its divisors is an integer number (6589160391).

Almost surely, 2^13178320781 is an apocalyptic number.

It is an amenable number.

13178320781 is a deficient number, since it is larger than the sum of its proper divisors (1).

13178320781 is an equidigital number, since it uses as much as digits as its factorization.

13178320781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 41.

The spelling of 13178320781 in words is "thirteen billion, one hundred seventy-eight million, three hundred twenty thousand, seven hundred eighty-one".