18660554777 has 2 divisors, whose sum is σ = 18660554778. Its totient is φ = 18660554776.

The previous prime is 18660554743. The next prime is 18660554819. The reversal of 18660554777 is 77745506681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18599777161 + 60777616 = 136381^2 + 7796^2 .

It is a cyclic number.

It is not a de Polignac number, because 18660554777 - 2¹⁰ = 18660553753 is a prime.

It is not a weakly prime, because it can be changed into another prime (18660554477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9330277388 + 9330277389.

It is an arithmetic number, because the mean of its divisors is an integer number (9330277389).

Almost surely, 2^18660554777 is an apocalyptic number.

It is an amenable number.

18660554777 is a deficient number, since it is larger than the sum of its proper divisors (1).

18660554777 is an equidigital number, since it uses as much as digits as its factorization.

18660554777 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9878400, while the sum is 56.

The spelling of 18660554777 in words is "eighteen billion, six hundred sixty million, five hundred fifty-four thousand, seven hundred seventy-seven".