209171712099 has 12 divisors (see below), whose sum is σ = 324429594504. Its totient is φ = 119526692544.

The previous prime is 209171712059. The next prime is 209171712107. The reversal of 209171712099 is 990217171902.

It is not a de Polignac number, because 209171712099 - 2⁷ = 209171711971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209171712019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 711468262 + ... + 711468555.

It is an arithmetic number, because the mean of its divisors is an integer number (27035799542).

Almost surely, 2^209171712099 is an apocalyptic number.

209171712099 is a deficient number, since it is larger than the sum of its proper divisors (115257882405).

209171712099 is a wasteful number, since it uses less digits than its factorization.

209171712099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1422936834 (or 1422936827 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 48.

The spelling of 209171712099 in words is "two hundred nine billion, one hundred seventy-one million, seven hundred twelve thousand, ninety-nine".