9809090909 has 4 divisors (see below), whose sum is σ = 9969895740. Its totient is φ = 9648286080.

The previous prime is 9809090891. The next prime is 9809090969. The reversal of 9809090909 is 9090909089.

It is a happy number.

9809090909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9090909089 = 2549 ⋅3566461.

It can be written as a sum of positive squares in 2 ways, for example, as 1507147684 + 8301943225 = 38822^2 + 91115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9809090909 is a prime.

It is a super-2 number, since 2×9809090909² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

9809090909 is a modest number, since divided by 90909 gives 9809 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9809090969) 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 in 3 ways as a sum of consecutive naturals, for example, 80402324 + ... + 80402445.

It is an arithmetic number, because the mean of its divisors is an integer number (2492473935).

Almost surely, 2^9809090909 is an apocalyptic number.

It is an amenable number.

9809090909 is a deficient number, since it is larger than the sum of its proper divisors (160804831).

9809090909 is a wasteful number, since it uses less digits than its factorization.

9809090909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160804830.

The product of its (nonzero) digits is 472392, while the sum is 53.

The square root of 9809090909 is about 99040.8547469174. The cubic root of 9809090909 is about 2140.6364681088.

The spelling of 9809090909 in words is "nine billion, eight hundred nine million, ninety thousand, nine hundred nine".