78316987181 has 2 divisors, whose sum is σ = 78316987182. Its totient is φ = 78316987180.

The previous prime is 78316987153. The next prime is 78316987201. The reversal of 78316987181 is 18178961387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54634855081 + 23682132100 = 233741^2 + 153890^2 .

It is an emirp because it is prime and its reverse (18178961387) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78316987181 - 2¹⁰ = 78316986157 is a prime.

It is a super-2 number, since 2×78316987181² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78316987181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78316987381) 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, 39158493590 + 39158493591.

It is an arithmetic number, because the mean of its divisors is an integer number (39158493591).

Almost surely, 2^78316987181 is an apocalyptic number.

It is an amenable number.

78316987181 is a deficient number, since it is larger than the sum of its proper divisors (1).

78316987181 is an equidigital number, since it uses as much as digits as its factorization.

78316987181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4064256, while the sum is 59.

The spelling of 78316987181 in words is "seventy-eight billion, three hundred sixteen million, nine hundred eighty-seven thousand, one hundred eighty-one".