66056717171565 has 12 divisors (see below), whose sum is σ = 114498309764124. Its totient is φ = 35230249158144.

The previous prime is 66056717171563. The next prime is 66056717171567. The reversal of 66056717171565 is 56517171765066.

66056717171565 is a `hidden beast` number, since 6 + 6 + 0 + 5 + 67 + 1 + 7 + 1 + 7 + 1 + 565 = 666.

66056717171565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66056717171563) and next prime (66056717171567).

It can be written as a sum of positive squares in 2 ways, for example, as 42702800728644 + 23353916442921 = 6534738^2 + 4832589^2 .

It is not a de Polignac number, because 66056717171565 - 2¹ = 66056717171563 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66056717171563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 733963524084 + ... + 733963524173.

It is an arithmetic number, because the mean of its divisors is an integer number (9541525813677).

Almost surely, 2^{66056717171565} is an apocalyptic number.

It is an amenable number.

66056717171565 is a deficient number, since it is larger than the sum of its proper divisors (48441592592559).

66056717171565 is a wasteful number, since it uses less digits than its factorization.

66056717171565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1467927048268 (or 1467927048265 counting only the distinct ones).

The product of its (nonzero) digits is 55566000, while the sum is 63.

The spelling of 66056717171565 in words is "sixty-six trillion, fifty-six billion, seven hundred seventeen million, one hundred seventy-one thousand, five hundred sixty-five".