491319569 has 4 divisors (see below), whose sum is σ = 529113396. Its totient is φ = 453525744.

The previous prime is 491319557. The next prime is 491319599. The reversal of 491319569 is 965913194.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 312829969 + 178489600 = 17687^2 + 13360^2 .

It is a cyclic number.

It is not a de Polignac number, because 491319569 - 2²⁸ = 222884113 is a prime.

It is a super-2 number, since 2×491319569² = 482789837764691522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491319599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18896894 + ... + 18896919.

It is an arithmetic number, because the mean of its divisors is an integer number (132278349).

Almost surely, 2^491319569 is an apocalyptic number.

It is an amenable number.

491319569 is a deficient number, since it is larger than the sum of its proper divisors (37793827).

491319569 is a wasteful number, since it uses less digits than its factorization.

491319569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37793826.

The product of its digits is 262440, while the sum is 47.

The square root of 491319569 is about 22165.7296067601. The cubic root of 491319569 is about 789.0805780747.

The spelling of 491319569 in words is "four hundred ninety-one million, three hundred nineteen thousand, five hundred sixty-nine".