16636398889 has 4 divisors (see below), whose sum is σ = 18148798800. Its totient is φ = 15123998980.

The previous prime is 16636398853. The next prime is 16636398913. The reversal of 16636398889 is 98889363661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98889363661 = 11 ⋅8989942151.

It is a cyclic number.

It is not a de Polignac number, because 16636398889 - 2¹⁵ = 16636366121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16636398839) 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, 756199939 + ... + 756199960.

It is an arithmetic number, because the mean of its divisors is an integer number (4537199700).

Almost surely, 2^16636398889 is an apocalyptic number.

It is an amenable number.

16636398889 is a deficient number, since it is larger than the sum of its proper divisors (1512399911).

16636398889 is a wasteful number, since it uses less digits than its factorization.

16636398889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1512399910.

The product of its digits is 80621568, while the sum is 67.

The spelling of 16636398889 in words is "sixteen billion, six hundred thirty-six million, three hundred ninety-eight thousand, eight hundred eighty-nine".