78691288129 has 2 divisors, whose sum is σ = 78691288130. Its totient is φ = 78691288128.

The previous prime is 78691288103. The next prime is 78691288141. The reversal of 78691288129 is 92188219687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52325647504 + 26365640625 = 228748^2 + 162375^2 .

It is a cyclic number.

It is not a de Polignac number, because 78691288129 - 2⁷ = 78691288001 is a prime.

It is not a weakly prime, because it can be changed into another prime (78691288229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39345644064 + 39345644065.

It is an arithmetic number, because the mean of its divisors is an integer number (39345644065).

Almost surely, 2^78691288129 is an apocalyptic number.

It is an amenable number.

78691288129 is a deficient number, since it is larger than the sum of its proper divisors (1).

78691288129 is an equidigital number, since it uses as much as digits as its factorization.

78691288129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6967296, while the sum is 61.

The spelling of 78691288129 in words is "seventy-eight billion, six hundred ninety-one million, two hundred eighty-eight thousand, one hundred twenty-nine".