206621896091 has 16 divisors (see below), whose sum is σ = 223854422400. Its totient is φ = 189583856640.

The previous prime is 206621896051. The next prime is 206621896157. The reversal of 206621896091 is 190698126602.

It is a cyclic number.

It is not a de Polignac number, because 206621896091 - 2¹⁴ = 206621879707 is a prime.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206621896051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1457735 + ... + 1593183.

It is an arithmetic number, because the mean of its divisors is an integer number (13990901400).

Almost surely, 2^206621896091 is an apocalyptic number.

206621896091 is a deficient number, since it is larger than the sum of its proper divisors (17232526309).

206621896091 is a wasteful number, since it uses less digits than its factorization.

206621896091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136166.

The product of its (nonzero) digits is 559872, while the sum is 50.

The spelling of 206621896091 in words is "two hundred six billion, six hundred twenty-one million, eight hundred ninety-six thousand, ninety-one".