66566140477 has 2 divisors, whose sum is σ = 66566140478. Its totient is φ = 66566140476.

The previous prime is 66566140451. The next prime is 66566140481. The reversal of 66566140477 is 77404166566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42907393881 + 23658746596 = 207141^2 + 153814^2 .

It is a cyclic number.

It is not a de Polignac number, because 66566140477 - 2¹⁵ = 66566107709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66566140777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33283070238 + 33283070239.

It is an arithmetic number, because the mean of its divisors is an integer number (33283070239).

Almost surely, 2^66566140477 is an apocalyptic number.

It is an amenable number.

66566140477 is a deficient number, since it is larger than the sum of its proper divisors (1).

66566140477 is an equidigital number, since it uses as much as digits as its factorization.

66566140477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5080320, while the sum is 52.

The spelling of 66566140477 in words is "sixty-six billion, five hundred sixty-six million, one hundred forty thousand, four hundred seventy-seven".