66744810667 has 4 divisors (see below), whose sum is σ = 66778302280. Its totient is φ = 66711319056.

The previous prime is 66744810641. The next prime is 66744810701. The reversal of 66744810667 is 76601844766.

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 66744810667 - 2¹¹ = 66744808619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66744810767) 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, 16742817 + ... + 16746802.

It is an arithmetic number, because the mean of its divisors is an integer number (16694575570).

Almost surely, 2^66744810667 is an apocalyptic number.

66744810667 is a deficient number, since it is larger than the sum of its proper divisors (33491613).

66744810667 is a wasteful number, since it uses less digits than its factorization.

66744810667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33491612.

The product of its (nonzero) digits is 8128512, while the sum is 55.

The spelling of 66744810667 in words is "sixty-six billion, seven hundred forty-four million, eight hundred ten thousand, six hundred sixty-seven".