66888888886665 has 48 divisors (see below), whose sum is σ = 126993914845200. Its totient is φ = 32417819836416.

The previous prime is 66888888886657. The next prime is 66888888886747. The reversal of 66888888886665 is 56668888888866.

66888888886665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 1200911331321 + 65687977555344 = 1095861^2 + 8104812^2 .

It is not a de Polignac number, because 66888888886665 - 2³ = 66888888886657 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1507502920 + ... + 1507547289.

It is an arithmetic number, because the mean of its divisors is an integer number (2645706559275).

Almost surely, 2^{66888888886665} is an apocalyptic number.

It is an amenable number.

66888888886665 is a deficient number, since it is larger than the sum of its proper divisors (60105025958535).

66888888886665 is a wasteful number, since it uses less digits than its factorization.

66888888886665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3015050266 (or 3015050263 counting only the distinct ones).

The product of its digits is 652298158080, while the sum is 99.

The spelling of 66888888886665 in words is "sixty-six trillion, eight hundred eighty-eight billion, eight hundred eighty-eight million, eight hundred eighty-six thousand, six hundred sixty-five".