66786646663 has 8 divisors (see below), whose sum is σ = 72876779136. Its totient is φ = 60699617400.

The previous prime is 66786646657. The next prime is 66786646669. The reversal of 66786646663 is 36664668766.

It is an interprime number because it is at equal distance from previous prime (66786646657) and next prime (66786646669).

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

It is a cyclic number.

It is not a de Polignac number, because 66786646663 - 2⁵ = 66786646631 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66786646595 and 66786646604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66786646669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 730683 + ... + 816988.

It is an arithmetic number, because the mean of its divisors is an integer number (9109597392).

Almost surely, 2^66786646663 is an apocalyptic number.

66786646663 is a deficient number, since it is larger than the sum of its proper divisors (6090132473).

66786646663 is a wasteful number, since it uses less digits than its factorization.

66786646663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1551605.

The product of its digits is 188116992, while the sum is 64.

The spelling of 66786646663 in words is "sixty-six billion, seven hundred eighty-six million, six hundred forty-six thousand, six hundred sixty-three".