491556191 has 12 divisors (see below), whose sum is σ = 572383512. Its totient is φ = 420911568.

The previous prime is 491556151. The next prime is 491556203. The reversal of 491556191 is 191655194.

It is not a de Polignac number, because 491556191 - 2¹⁰ = 491555167 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491556151) 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 11 ways as a sum of consecutive naturals, for example, 50561 + ... + 59493.

It is an arithmetic number, because the mean of its divisors is an integer number (47698626).

Almost surely, 2^491556191 is an apocalyptic number.

491556191 is a deficient number, since it is larger than the sum of its proper divisors (80827321).

491556191 is a wasteful number, since it uses less digits than its factorization.

491556191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10070 (or 10063 counting only the distinct ones).

The product of its digits is 48600, while the sum is 41.

The square root of 491556191 is about 22171.0665282480. The cubic root of 491556191 is about 789.2072328158.

The spelling of 491556191 in words is "four hundred ninety-one million, five hundred fifty-six thousand, one hundred ninety-one".