18775457777 has 2 divisors, whose sum is σ = 18775457778. Its totient is φ = 18775457776.

The previous prime is 18775457761. The next prime is 18775457783. The reversal of 18775457777 is 77775457781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17618845696 + 1156612081 = 132736^2 + 34009^2 .

It is a cyclic number.

It is not a de Polignac number, because 18775457777 - 2⁴ = 18775457761 is a prime.

It is not a weakly prime, because it can be changed into another prime (18775457377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9387728888 + 9387728889.

It is an arithmetic number, because the mean of its divisors is an integer number (9387728889).

Almost surely, 2^18775457777 is an apocalyptic number.

It is an amenable number.

18775457777 is a deficient number, since it is larger than the sum of its proper divisors (1).

18775457777 is an equidigital number, since it uses as much as digits as its factorization.

18775457777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94119200, while the sum is 65.

The spelling of 18775457777 in words is "eighteen billion, seven hundred seventy-five million, four hundred fifty-seven thousand, seven hundred seventy-seven".