8491087118809 has 9 divisors (see below), whose sum is σ = 8505409950111. Its totient is φ = 8476788380880.

The previous prime is 8491087118753. The next prime is 8491087118819. The reversal of 8491087118809 is 9088117801948.

The square root of 8491087118809 is 2913947.

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., 7544498225625 + 946588893184 = 2746725^2 + 972928^2 .

It is not a de Polignac number, because 8491087118809 - 2⁷ = 8491087118681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8491087118819) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2013535269 + ... + 2013539485.

Almost surely, 2^{8491087118809} is an apocalyptic number.

8491087118809 is the 2913947-th square number.

8491087118809 is the 1456974-th centered octagonal number.

It is an amenable number.

8491087118809 is a deficient number, since it is larger than the sum of its proper divisors (14322831302).

8491087118809 is an frugal number, since it uses more digits than its factorization.

8491087118809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9816 (or 4908 counting only the distinct ones).

The product of its (nonzero) digits is 9289728, while the sum is 64.

Multiplying 8491087118809 by its sum of digits (64), we get a square (543429575603776 = 23311576²).

The spelling of 8491087118809 in words is "eight trillion, four hundred ninety-one billion, eighty-seven million, one hundred eighteen thousand, eight hundred nine".