20111100209 has 2 divisors, whose sum is σ = 20111100210. Its totient is φ = 20111100208.

The previous prime is 20111100193. The next prime is 20111100227. The reversal of 20111100209 is 90200111102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20079740209 + 31360000 = 141703^2 + 5600^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111100209 - 2⁴ = 20111100193 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20111100299) 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 as a sum of consecutive naturals, namely, 10055550104 + 10055550105.

It is an arithmetic number, because the mean of its divisors is an integer number (10055550105).

Almost surely, 2^20111100209 is an apocalyptic number.

It is an amenable number.

20111100209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111100209 is an equidigital number, since it uses as much as digits as its factorization.

20111100209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 17.

The spelling of 20111100209 in words is "twenty billion, one hundred eleven million, one hundred thousand, two hundred nine".