99668384209 has 3 divisors (see below), whose sum is σ = 99668699913. Its totient is φ = 99668068506.

The previous prime is 99668384183. The next prime is 99668384237. The reversal of 99668384209 is 90248386699.

The square root of 99668384209 is 315703.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 99668384209 - 2²¹ = 99666287057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99668384269) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 157852 + ... + 473554.

It is an arithmetic number, because the mean of its divisors is an integer number (33222899971).

Almost surely, 2^99668384209 is an apocalyptic number.

99668384209 is the 315703-rd square number.

99668384209 is the 157852-nd centered octagonal number.

It is an amenable number.

99668384209 is a deficient number, since it is larger than the sum of its proper divisors (315704).

99668384209 is an frugal number, since it uses more digits than its factorization.

99668384209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631406 (or 315703 counting only the distinct ones).

The product of its (nonzero) digits is 40310784, while the sum is 64.

Multiplying 99668384209 by its sum of digits (64), we get a square (6378776589376 = 2525624²).

The spelling of 99668384209 in words is "ninety-nine billion, six hundred sixty-eight million, three hundred eighty-four thousand, two hundred nine".