66807478477 has 2 divisors, whose sum is σ = 66807478478. Its totient is φ = 66807478476.

The previous prime is 66807478429. The next prime is 66807478589. The reversal of 66807478477 is 77487470866.

66807478477 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., 51970776841 + 14836701636 = 227971^2 + 121806^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66807478477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66807478877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33403739238 + 33403739239.

It is an arithmetic number, because the mean of its divisors is an integer number (33403739239).

Almost surely, 2^66807478477 is an apocalyptic number.

It is an amenable number.

66807478477 is a deficient number, since it is larger than the sum of its proper divisors (1).

66807478477 is an equidigital number, since it uses as much as digits as its factorization.

66807478477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 88510464, while the sum is 64.

The spelling of 66807478477 in words is "sixty-six billion, eight hundred seven million, four hundred seventy-eight thousand, four hundred seventy-seven".