20204040209 has 2 divisors, whose sum is σ = 20204040210. Its totient is φ = 20204040208.

The previous prime is 20204040191. The next prime is 20204040239. The reversal of 20204040209 is 90204040202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17570297809 + 2633742400 = 132553^2 + 51320^2 .

It is a cyclic number.

It is not a de Polignac number, because 20204040209 - 2¹² = 20204036113 is a prime.

It is not a weakly prime, because it can be changed into another prime (20204040239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10102020104 + 10102020105.

It is an arithmetic number, because the mean of its divisors is an integer number (10102020105).

Almost surely, 2^20204040209 is an apocalyptic number.

It is an amenable number.

20204040209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20204040209 is an equidigital number, since it uses as much as digits as its factorization.

20204040209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 23.

The spelling of 20204040209 in words is "twenty billion, two hundred four million, forty thousand, two hundred nine".