66685658665 has 8 divisors (see below), whose sum is σ = 80341607808. Its totient is φ = 53135982000.

The previous prime is 66685658657. The next prime is 66685658701. The reversal of 66685658665 is 56685658666.

66685658665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 66685658665 - 2³ = 66685658657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66685658665.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26566737 + ... + 26569246.

It is an arithmetic number, because the mean of its divisors is an integer number (10042700976).

Almost surely, 2^66685658665 is an apocalyptic number.

It is an amenable number.

66685658665 is a deficient number, since it is larger than the sum of its proper divisors (13655949143).

66685658665 is a wasteful number, since it uses less digits than its factorization.

66685658665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53136239.

The product of its digits is 373248000, while the sum is 67.

Subtracting from 66685658665 its reverse (56685658666), we obtain a palindrome (9999999999).

The spelling of 66685658665 in words is "sixty-six billion, six hundred eighty-five million, six hundred fifty-eight thousand, six hundred sixty-five".