66666688888889 has 4 divisors (see below), whose sum is σ = 66783443160720. Its totient is φ = 66549934617060.

The previous prime is 66666688888873. The next prime is 66666688888901. The reversal of 66666688888889 is 98888888666666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66666688888889 - 2⁴ = 66666688888873 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66666688888589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58377135059 + ... + 58377136200.

It is an arithmetic number, because the mean of its divisors is an integer number (16695860790180).

Almost surely, 2^{66666688888889} is an apocalyptic number.

It is an amenable number.

66666688888889 is a deficient number, since it is larger than the sum of its proper divisors (116754271831).

66666688888889 is a wasteful number, since it uses less digits than its factorization.

66666688888889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116754271830.

The product of its digits is 880602513408, while the sum is 101.

The spelling of 66666688888889 in words is "sixty-six trillion, six hundred sixty-six billion, six hundred eighty-eight million, eight hundred eighty-eight thousand, eight hundred eighty-nine".