491116509 has 12 divisors (see below), whose sum is σ = 763959196. Its totient is φ = 302225472.

The previous prime is 491116487. The next prime is 491116513. The reversal of 491116509 is 905611194.

491116509 is a `hidden beast` number, since 491 + 1 + 165 + 0 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 81054009 + 410062500 = 9003^2 + 20250^2 .

It is not a de Polignac number, because 491116509 - 2⁹ = 491115997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491116589) 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 11 ways as a sum of consecutive naturals, for example, 2098672 + ... + 2098905.

Almost surely, 2^491116509 is an apocalyptic number.

It is an amenable number.

491116509 is a deficient number, since it is larger than the sum of its proper divisors (272842687).

491116509 is a wasteful number, since it uses less digits than its factorization.

491116509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4197596 (or 4197593 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 491116509 is about 22161.1486390033. The cubic root of 491116509 is about 788.9718553672.

The spelling of 491116509 in words is "four hundred ninety-one million, one hundred sixteen thousand, five hundred nine".