209188794469 has 4 divisors (see below), whose sum is σ = 220198731040. Its totient is φ = 198178857900.

The previous prime is 209188794421. The next prime is 209188794473. The reversal of 209188794469 is 964497881902.

209188794469 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 209188794469 - 2³⁷ = 71749840997 is a prime.

It is a super-2 number, since 2×209188794469² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209188794569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5504968257 + ... + 5504968294.

It is an arithmetic number, because the mean of its divisors is an integer number (55049682760).

Almost surely, 2^209188794469 is an apocalyptic number.

It is an amenable number.

209188794469 is a deficient number, since it is larger than the sum of its proper divisors (11009936571).

209188794469 is a wasteful number, since it uses less digits than its factorization.

209188794469 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11009936570.

The product of its (nonzero) digits is 62705664, while the sum is 67.

The spelling of 209188794469 in words is "two hundred nine billion, one hundred eighty-eight million, seven hundred ninety-four thousand, four hundred sixty-nine".