91818090065 has 32 divisors (see below), whose sum is σ = 119502462240. Its totient is φ = 67322198016.

The previous prime is 91818090059. The next prime is 91818090097. The reversal of 91818090065 is 56009081819.

It can be written as a sum of positive squares in 16 ways, for example, as 3556810321 + 88261279744 = 59639^2 + 297088^2 .

It is a cyclic number.

It is not a de Polignac number, because 91818090065 - 2¹⁴ = 91818073681 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 9092159 + ... + 9102251.

It is an arithmetic number, because the mean of its divisors is an integer number (3734451945).

Almost surely, 2^91818090065 is an apocalyptic number.

It is an amenable number.

91818090065 is a deficient number, since it is larger than the sum of its proper divisors (27684372175).

91818090065 is a wasteful number, since it uses less digits than its factorization.

91818090065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11093.

The product of its (nonzero) digits is 155520, while the sum is 47.

The spelling of 91818090065 in words is "ninety-one billion, eight hundred eighteen million, ninety thousand, sixty-five".