66517214081 has 2 divisors, whose sum is σ = 66517214082. Its totient is φ = 66517214080.

The previous prime is 66517214077. The next prime is 66517214087. The reversal of 66517214081 is 18041271566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64727501056 + 1789713025 = 254416^2 + 42305^2 .

It is a cyclic number.

It is not a de Polignac number, because 66517214081 - 2² = 66517214077 is a prime.

It is a super-3 number, since 3×66517214081³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (66517214087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33258607040 + 33258607041.

It is an arithmetic number, because the mean of its divisors is an integer number (33258607041).

Almost surely, 2^66517214081 is an apocalyptic number.

It is an amenable number.

66517214081 is a deficient number, since it is larger than the sum of its proper divisors (1).

66517214081 is an equidigital number, since it uses as much as digits as its factorization.

66517214081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 41.

The spelling of 66517214081 in words is "sixty-six billion, five hundred seventeen million, two hundred fourteen thousand, eighty-one".