909090109 has 2 divisors, whose sum is σ = 909090110. Its totient is φ = 909090108.

The previous prime is 909090107. The next prime is 909090179. The reversal of 909090109 is 901090909.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 881496100 + 27594009 = 29690^2 + 5253^2 .

It is a cyclic number.

It is not a de Polignac number, because 909090109 - 2¹ = 909090107 is a prime.

Together with 909090107, it forms a pair of twin primes.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (909090107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 454545054 + 454545055.

It is an arithmetic number, because the mean of its divisors is an integer number (454545055).

Almost surely, 2^909090109 is an apocalyptic number.

It is an amenable number.

909090109 is a deficient number, since it is larger than the sum of its proper divisors (1).

909090109 is an equidigital number, since it uses as much as digits as its factorization.

909090109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6561, while the sum is 37.

The square root of 909090109 is about 30151.1211897667. The cubic root of 909090109 is about 968.7290219585.

It can be divided in two parts, 9090 and 90109, that added together give a palindrome (99199).

The spelling of 909090109 in words is "nine hundred nine million, ninety thousand, one hundred nine".