909091 has 2 divisors, whose sum is σ = 909092. Its totient is φ = 909090.

The previous prime is 909089. The next prime is 909107. The reversal of 909091 is 190909.

It is a weak prime.

It is an emirp because it is prime and its reverse (190909) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 909091 - 2¹ = 909089 is a prime.

Together with 909089, it forms a pair of twin primes.

909091 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (909031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 454545 + 454546.

It is an arithmetic number, because the mean of its divisors is an integer number (454546).

2⁹⁰⁹⁰⁹¹ is an apocalyptic number.

909091 is a deficient number, since it is larger than the sum of its proper divisors (1).

909091 is an equidigital number, since it uses as much as digits as its factorization.

909091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729, while the sum is 28.

The square root of 909091 is about 953.4626369187. The cubic root of 909091 is about 96.8729338442.

The spelling of 909091 in words is "nine hundred nine thousand, ninety-one".