66748084765 has 4 divisors (see below), whose sum is σ = 80097701724. Its totient is φ = 53398467808.

The previous prime is 66748084709. The next prime is 66748084783. The reversal of 66748084765 is 56748084766.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56748084766 = 2 ⋅28374042383.

It can be written as a sum of positive squares in 2 ways, for example, as 15752509081 + 50995575684 = 125509^2 + 225822^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66748084765 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6674808472 + ... + 6674808481.

It is an arithmetic number, because the mean of its divisors is an integer number (20024425431).

Almost surely, 2^66748084765 is an apocalyptic number.

It is an amenable number.

66748084765 is a deficient number, since it is larger than the sum of its proper divisors (13349616959).

66748084765 is a wasteful number, since it uses less digits than its factorization.

66748084765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13349616958.

The product of its (nonzero) digits is 54190080, while the sum is 61.

Subtracting from 66748084765 its reverse (56748084766), we obtain a palindrome (9999999999).

The spelling of 66748084765 in words is "sixty-six billion, seven hundred forty-eight million, eighty-four thousand, seven hundred sixty-five".