78445727677 has 2 divisors, whose sum is σ = 78445727678. Its totient is φ = 78445727676.

The previous prime is 78445727669. The next prime is 78445727683. The reversal of 78445727677 is 77672754487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74722409316 + 3723318361 = 273354^2 + 61019^2 .

It is a cyclic number.

It is not a de Polignac number, because 78445727677 - 2³ = 78445727669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78445727617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39222863838 + 39222863839.

It is an arithmetic number, because the mean of its divisors is an integer number (39222863839).

Almost surely, 2^78445727677 is an apocalyptic number.

It is an amenable number.

78445727677 is a deficient number, since it is larger than the sum of its proper divisors (1).

78445727677 is an equidigital number, since it uses as much as digits as its factorization.

78445727677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129077760, while the sum is 64.

The spelling of 78445727677 in words is "seventy-eight billion, four hundred forty-five million, seven hundred twenty-seven thousand, six hundred seventy-seven".