66991116699 has 24 divisors (see below), whose sum is σ = 104470965872. Its totient is φ = 41121432000.

The previous prime is 66991116679. The next prime is 66991116707. The reversal of 66991116699 is 99661119966.

It is not a de Polignac number, because 66991116699 - 2⁷ = 66991116571 is a prime.

It is a super-3 number, since 3×66991116699³ (a number of 33 digits) contains 333 as substring.

66991116699 is a strobogrammatic number because it is the same when read upside-down.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66991116659) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 674677 + ... + 767574.

Almost surely, 2^66991116699 is an apocalyptic number.

66991116699 is a deficient number, since it is larger than the sum of its proper divisors (37479849173).

66991116699 is a wasteful number, since it uses less digits than its factorization.

66991116699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1442667 (or 1442664 counting only the distinct ones).

The product of its digits is 8503056, while the sum is 63.

The spelling of 66991116699 in words is "sixty-six billion, nine hundred ninety-one million, one hundred sixteen thousand, six hundred ninety-nine".