491915965 has 4 divisors (see below), whose sum is σ = 590299164. Its totient is φ = 393532768.

The previous prime is 491915953. The next prime is 491915969. The reversal of 491915965 is 569519194.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 569519194 = 2 ⋅284759597.

It can be written as a sum of positive squares in 2 ways, for example, as 230705721 + 261210244 = 15189^2 + 16162^2 .

It is a cyclic number.

It is not a de Polignac number, because 491915965 - 2⁵ = 491915933 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491915969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49191592 + ... + 49191601.

It is an arithmetic number, because the mean of its divisors is an integer number (147574791).

Almost surely, 2^491915965 is an apocalyptic number.

It is an amenable number.

491915965 is a deficient number, since it is larger than the sum of its proper divisors (98383199).

491915965 is an equidigital number, since it uses as much as digits as its factorization.

491915965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98383198.

The product of its digits is 437400, while the sum is 49.

The square root of 491915965 is about 22179.1786367304. The cubic root of 491915965 is about 789.3997282718.

The spelling of 491915965 in words is "four hundred ninety-one million, nine hundred fifteen thousand, nine hundred sixty-five".