66566332081 has 6 divisors (see below), whose sum is σ = 70712332310. Its totient is φ = 62650665216.

The previous prime is 66566332051. The next prime is 66566332093. The reversal of 66566332081 is 18023366566.

It can be written as a sum of positive squares in 3 ways, for example, as 41298368400 + 25267963681 = 203220^2 + 158959^2 .

It is not a de Polignac number, because 66566332081 - 2¹⁵ = 66566299313 is a prime.

It is a super-2 number, since 2×66566332081² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66566332031) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 115166376 + ... + 115166953.

Almost surely, 2^66566332081 is an apocalyptic number.

It is an amenable number.

66566332081 is a deficient number, since it is larger than the sum of its proper divisors (4146000229).

66566332081 is a wasteful number, since it uses less digits than its factorization.

66566332081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230333363 (or 230333346 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 66566332081 in words is "sixty-six billion, five hundred sixty-six million, three hundred thirty-two thousand, eighty-one".