91323026809 has 27 divisors (see below), whose sum is σ = 111111745647. Its totient is φ = 74833647504.

The previous prime is 91323026789. The next prime is 91323026909. The reversal of 91323026809 is 90862032319.

The square root of 91323026809 is 302197.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 57161637225 + 34161389584 = 239085^2 + 184828^2 .

It is not a de Polignac number, because 91323026809 - 2¹⁷ = 91322895737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91323026309) 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 in 26 ways as a sum of consecutive naturals, for example, 48652779 + ... + 48654655.

Almost surely, 2^91323026809 is an apocalyptic number.

91323026809 is the 302197-th square number.

91323026809 is the 151099-th centered octagonal number.

It is an amenable number.

91323026809 is a deficient number, since it is larger than the sum of its proper divisors (19788718838).

91323026809 is an frugal number, since it uses more digits than its factorization.

91323026809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3814 (or 1907 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 91323026809 in words is "ninety-one billion, three hundred twenty-three million, twenty-six thousand, eight hundred nine".