66718417847 has 4 divisors (see below), whose sum is σ = 66735428760. Its totient is φ = 66701406936.

The previous prime is 66718417771. The next prime is 66718417873. The reversal of 66718417847 is 74871481766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66718417847 - 2¹⁰ = 66718416823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66718417897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8499572 + ... + 8507417.

It is an arithmetic number, because the mean of its divisors is an integer number (16683857190).

Almost surely, 2^66718417847 is an apocalyptic number.

66718417847 is a deficient number, since it is larger than the sum of its proper divisors (17010913).

66718417847 is a wasteful number, since it uses less digits than its factorization.

66718417847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17010912.

The product of its digits is 12644352, while the sum is 59.

The spelling of 66718417847 in words is "sixty-six billion, seven hundred eighteen million, four hundred seventeen thousand, eight hundred forty-seven".