66681686017 has 8 divisors (see below), whose sum is σ = 66733615872. Its totient is φ = 66629781600.

The previous prime is 66681685991. The next prime is 66681686059. The reversal of 66681686017 is 71068618666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66681686017 - 2³⁵ = 32321947649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66681686087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12744792 + ... + 12750022.

It is an arithmetic number, because the mean of its divisors is an integer number (8341701984).

Almost surely, 2^66681686017 is an apocalyptic number.

It is an amenable number.

66681686017 is a deficient number, since it is larger than the sum of its proper divisors (51929855).

66681686017 is a wasteful number, since it uses less digits than its factorization.

66681686017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12719.

The product of its (nonzero) digits is 3483648, while the sum is 55.

The spelling of 66681686017 in words is "sixty-six billion, six hundred eighty-one million, six hundred eighty-six thousand, seventeen".