78628551677677 has 2 divisors, whose sum is σ = 78628551677678. Its totient is φ = 78628551677676.

The previous prime is 78628551677593. The next prime is 78628551677747. The reversal of 78628551677677 is 77677615582687.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58662900407241 + 19965651270436 = 7659171^2 + 4468294^2 .

It is a cyclic number.

It is not a de Polignac number, because 78628551677677 - 2¹¹ = 78628551675629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78628551677677.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78628554677677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39314275838838 + 39314275838839.

It is an arithmetic number, because the mean of its divisors is an integer number (39314275838839).

Almost surely, 2^{78628551677677} is an apocalyptic number.

It is an amenable number.

78628551677677 is a deficient number, since it is larger than the sum of its proper divisors (1).

78628551677677 is an equidigital number, since it uses as much as digits as its factorization.

78628551677677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11616998400, while the sum is 82.

The spelling of 78628551677677 in words is "seventy-eight trillion, six hundred twenty-eight billion, five hundred fifty-one million, six hundred seventy-seven thousand, six hundred seventy-seven".