16531021834209 has 6 divisors (see below), whose sum is σ = 23878142649426. Its totient is φ = 11020681222800.

The previous prime is 16531021834183. The next prime is 16531021834267. The reversal of 16531021834209 is 90243812013561.

16531021834209 is a `hidden beast` number, since 1 + 6 + 5 + 3 + 1 + 0 + 218 + 3 + 420 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13001613350625 + 3529408483584 = 3605775^2 + 1878672^2 .

It is not a de Polignac number, because 16531021834209 - 2⁷ = 16531021834081 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16531021834909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 918390101892 + ... + 918390101909.

It is an arithmetic number, because the mean of its divisors is an integer number (3979690441571).

Almost surely, 2^{16531021834209} is an apocalyptic number.

It is an amenable number.

16531021834209 is a deficient number, since it is larger than the sum of its proper divisors (7347120815217).

16531021834209 is a wasteful number, since it uses less digits than its factorization.

16531021834209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1836780203807 (or 1836780203804 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 16531021834209 in words is "sixteen trillion, five hundred thirty-one billion, twenty-one million, eight hundred thirty-four thousand, two hundred nine".