66599366691 has 16 divisors (see below), whose sum is σ = 104323484160. Its totient is φ = 37258386720.

The previous prime is 66599366681. The next prime is 66599366773. The reversal of 66599366691 is 19666399566.

It is not a de Polignac number, because 66599366691 - 2⁹ = 66599366179 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66599366621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77621211 + ... + 77622068.

It is an arithmetic number, because the mean of its divisors is an integer number (6520217760).

Almost surely, 2^66599366691 is an apocalyptic number.

66599366691 is a deficient number, since it is larger than the sum of its proper divisors (37724117469).

66599366691 is a wasteful number, since it uses less digits than its factorization.

66599366691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155243306.

The product of its digits is 85030560, while the sum is 66.

The spelling of 66599366691 in words is "sixty-six billion, five hundred ninety-nine million, three hundred sixty-six thousand, six hundred ninety-one".