491186560721 has 8 divisors (see below), whose sum is σ = 500483297664. Its totient is φ = 481890900400.

The previous prime is 491186560703. The next prime is 491186560747. The reversal of 491186560721 is 127065681194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 491186560721 - 2³⁸ = 216308653777 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 491186560721.

It is not an unprimeable number, because it can be changed into a prime (491186560771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 683546 + ... + 1203996.

It is an arithmetic number, because the mean of its divisors is an integer number (62560412208).

Almost surely, 2^491186560721 is an apocalyptic number.

It is an amenable number.

491186560721 is a deficient number, since it is larger than the sum of its proper divisors (9296736943).

491186560721 is a wasteful number, since it uses less digits than its factorization.

491186560721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538311.

The product of its (nonzero) digits is 725760, while the sum is 50.

The spelling of 491186560721 in words is "four hundred ninety-one billion, one hundred eighty-six million, five hundred sixty thousand, seven hundred twenty-one".