66746307217 has 2 divisors, whose sum is σ = 66746307218. Its totient is φ = 66746307216.

The previous prime is 66746307181. The next prime is 66746307269. The reversal of 66746307217 is 71270364766.

66746307217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35404561921 + 31341745296 = 188161^2 + 177036^2 .

It is a cyclic number.

It is not a de Polignac number, because 66746307217 - 2¹⁵ = 66746274449 is a prime.

It is a super-2 number, since 2×66746307217² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66746304217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33373153608 + 33373153609.

It is an arithmetic number, because the mean of its divisors is an integer number (33373153609).

Almost surely, 2^66746307217 is an apocalyptic number.

It is an amenable number.

66746307217 is a deficient number, since it is larger than the sum of its proper divisors (1).

66746307217 is an equidigital number, since it uses as much as digits as its factorization.

66746307217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1778112, while the sum is 49.

The spelling of 66746307217 in words is "sixty-six billion, seven hundred forty-six million, three hundred seven thousand, two hundred seventeen".