66865597177 has 2 divisors, whose sum is σ = 66865597178. Its totient is φ = 66865597176.

The previous prime is 66865597039. The next prime is 66865597199. The reversal of 66865597177 is 77179556866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34053535296 + 32812061881 = 184536^2 + 181141^2 .

It is a cyclic number.

It is not a de Polignac number, because 66865597177 - 2¹⁹ = 66865072889 is a prime.

It is not a weakly prime, because it can be changed into another prime (66865097177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33432798588 + 33432798589.

It is an arithmetic number, because the mean of its divisors is an integer number (33432798589).

Almost surely, 2^66865597177 is an apocalyptic number.

It is an amenable number.

66865597177 is a deficient number, since it is larger than the sum of its proper divisors (1).

66865597177 is an equidigital number, since it uses as much as digits as its factorization.

66865597177 is an evil number, because the sum of its binary digits is even.

The product of its digits is 133358400, while the sum is 67.

The spelling of 66865597177 in words is "sixty-six billion, eight hundred sixty-five million, five hundred ninety-seven thousand, one hundred seventy-seven".