9820440209 has 2 divisors, whose sum is σ = 9820440210. Its totient is φ = 9820440208.

The previous prime is 9820440199. The next prime is 9820440229. The reversal of 9820440209 is 9020440289.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7586932609 + 2233507600 = 87103^2 + 47260^2 .

It is a cyclic number.

It is not a de Polignac number, because 9820440209 - 2¹² = 9820436113 is a prime.

It is not a weakly prime, because it can be changed into another prime (9820440229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4910220104 + 4910220105.

It is an arithmetic number, because the mean of its divisors is an integer number (4910220105).

Almost surely, 2^9820440209 is an apocalyptic number.

It is an amenable number.

9820440209 is a deficient number, since it is larger than the sum of its proper divisors (1).

9820440209 is an equidigital number, since it uses as much as digits as its factorization.

9820440209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 9820440209 is about 99098.1342357161. The cubic root of 9820440209 is about 2141.4617352648.

The spelling of 9820440209 in words is "nine billion, eight hundred twenty million, four hundred forty thousand, two hundred nine".