18664216899 has 4 divisors (see below), whose sum is σ = 24885622536. Its totient is φ = 12442811264.

The previous prime is 18664216877. The next prime is 18664216919. The reversal of 18664216899 is 99861246681.

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 18664216899 - 2⁷ = 18664216771 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18664216829) 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, 3110702814 + ... + 3110702819.

It is an arithmetic number, because the mean of its divisors is an integer number (6221405634).

Almost surely, 2^18664216899 is an apocalyptic number.

18664216899 is a deficient number, since it is larger than the sum of its proper divisors (6221405637).

18664216899 is an equidigital number, since it uses as much as digits as its factorization.

18664216899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6221405636.

The product of its digits is 8957952, while the sum is 60.

The spelling of 18664216899 in words is "eighteen billion, six hundred sixty-four million, two hundred sixteen thousand, eight hundred ninety-nine".