66656665666 has 8 divisors (see below), whose sum is σ = 100183777344. Its totient is φ = 33262073220.

The previous prime is 66656665633. The next prime is 66656665693.

66656665666 is nontrivially palindromic in base 10.

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

It is a super-2 number, since 2×66656665666² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66656665598 and 66656665607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33128550 + ... + 33130561.

It is an arithmetic number, because the mean of its divisors is an integer number (12522972168).

Almost surely, 2^66656665666 is an apocalyptic number.

66656665666 is a deficient number, since it is larger than the sum of its proper divisors (33527111678).

66656665666 is a wasteful number, since it uses less digits than its factorization.

66656665666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66259616.

The product of its digits is 251942400, while the sum is 64.

The spelling of 66656665666 in words is "sixty-six billion, six hundred fifty-six million, six hundred sixty-five thousand, six hundred sixty-six".