9990209 has 2 divisors, whose sum is σ = 9990210. Its totient is φ = 9990208.

The previous prime is 9990193. The next prime is 9990221. The reversal of 9990209 is 9020999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9394225 + 595984 = 3065^2 + 772^2 .

It is a cyclic number.

It is not a de Polignac number, because 9990209 - 2⁴ = 9990193 is a prime.

It is not a weakly prime, because it can be changed into another prime (9990289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995104 + 4995105.

It is an arithmetic number, because the mean of its divisors is an integer number (4995105).

Almost surely, 2^9990209 is an apocalyptic number.

It is an amenable number.

9990209 is a deficient number, since it is larger than the sum of its proper divisors (1).

9990209 is an equidigital number, since it uses as much as digits as its factorization.

9990209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13122, while the sum is 38.

The square root of 9990209 is about 3160.7291880198. The cubic root of 9990209 is about 215.3731324759.

The spelling of 9990209 in words is "nine million, nine hundred ninety thousand, two hundred nine".